FORCES & MOTION 4.1 THE STUDENT WILL…USE EXAMPLES TO EXPLAIN THE CONCEPT OF INERTIA IN EVERYDAY SITUATIONS. 4.2 DESCRIBE THE RELATIONSHIP BETWEEN MASS

Embed Size (px)

Citation preview

  • Slide 1
  • FORCES & MOTION 4.1 THE STUDENT WILLUSE EXAMPLES TO EXPLAIN THE CONCEPT OF INERTIA IN EVERYDAY SITUATIONS. 4.2 DESCRIBE THE RELATIONSHIP BETWEEN MASS AND GRAVITY. 4.3 DESCRIBE THE FOLLOWING INTERACTIONS: SPEED, VELOCITY, AND ACCELERATION. 4.4 DRAW AND INTERPRET DIAGRAMS AND GRAPHS REPRESENTING AN OBJECTS MOTION. 4.5 DESCRIBE THE FOLLOWING FORCES: GRAVITY AND FRICTION. 4.6 PROVIDE EVIDENCE TO DEMONSTRATE THE RELATIONSHIP BETWEEN FORCE AND MOTION. P8B1 STUDENTS KNOW THE EFFECTS OF BALANCED AND UNBALANCED FORCES ON AN OBJECTS MOTION. 4.7 IDENTIFY THE FORCE(S) ACTING ON MOVING AND STATIONARY OBJECTS. 4.8 DETERMINE THE NET FORCE ON AN OBJECT GIVEN A DIAGRAM. P8B3 STUDENTS KNOW EVERY OBJECT EXERTS GRAVITATIONAL FORCE ON EVERY OTHER OBJECT, AND THE MAGNITUDE OF THIS FORCE DEPENDS ON THE MASS OF THE OBJECTS AND THEIR DISTANCE FROM ONE ANOTHER. 4.9 DESCRIBE THE RELATIONSHIP BETWEEN DISTANCE AND GRAVITY. 4.10 EXPLAIN THAT EVERY OBJECT EXERTS GRAVITATIONAL FORCE ON EVERY OTHER OBJECT.
  • Slide 2
  • ENERGY 7.1 THE STUDENT WILL USE AN OPERATIONAL DEFINITION OF ENERGY. 7.2 THE STUDENT WILL DEMONSTRATE THAT ENERGY CAN BE KINETIC OR POTENTIAL. 7.3 THE STUDENT WILL INVESTIGATE ENERGY AS A PROPERTY ASSOCIATED WITH MATTER. 7.4 THE STUDENT WILL DESCRIBE DIFFERENT FORMS OF ENERGY (MECHANICAL MOTION). 7.5 THE STUDENT WILL DESCRIBE VARIOUS ENERGY TRANSFERS WITHIN A SYSTEM. 7.7 THE STUDENT WILL GIVE EXAMPLES OF ENERGY TRANSFORMATIONS.
  • Slide 3
  • Bellwork- Wednesday 12/7/11 Identify the type of friction shown in each diagram. Sketch the pictures and draw arrows to show the direction of friction. Sliding Friction Two solid objects rubbing on each other. Rolling Friction Two solid objects; one rolls over the other. Fluid Friction A solid object that rubs against a fluid (liquid or gas).
  • Slide 4
  • MythBusters: Phone Book Friction Continued What has happened so far? What do you predict will happen? Will Adam and Jamie be able to separate the phone books? Myth Busters Video Part 2 (6 m 30 s) Air Resistance Videos What happens when there is no air resistance? Why? Hammer and Feather on Moon Video (47s) Ball and Feather in Vaccum Video (20 s)
  • Slide 5
  • Forces- page 13 P8B1- TSW KNOW THE EFFECTS OF BALANCED AND UNBALANCED FORCES ON AN OBJECTS MOTION Force - a push or pull Unit: Newtons (N) May change the motion of an object Forces can be represented by arrows The size of the arrow represents the magnitude (strength) and the point shows its direction Newton - unit of force 1 Newton is the force required to accelerate 1 kg of mass at 1 meter per second, per second (m/s) Net force- overall force after all forces on an object are combined together forces in the same direction combine by addition forces in opposite directions combine by subtraction
  • Slide 6
  • Combining Forces In which direction is the net force? + = =0 (balanced) = =
  • Slide 7
  • Bellwork- Thursday 12/7/11 A skydiver falls faster and faster through the air. Eventually her velocity will a) increase b) decrease c) remain constant How can you explain this? Terminal velocity- maximum (constant) velocity a falling object reaches; no longer accelerating; air resistance = gravity A cowboy drops his gun while riding his horse at a fast gallop. In the absence of air resistance, where will the gun hit the ground relative to the horse? a. In front of the horse b. Behind the horse c. Next to the horse Why? Gravity pulls gun down, but it will also continue to move straight forward with the same velocity as the horse (inertia- 1 st law of motion). There is no air to push it any other way.
  • Slide 8
  • Page 8 Distance-Time & Speed-Time Graphs 1. A, E, F 2. D 3. B, C 4. E 5. B, C, D, E, F 6. F 7. 2.5 y/s; 5 y/s 5 y/s; 2.5 y/s 5 y/s; 7.5 y/s 2.5 y/s; 2.5 y/s 7.5 y/s; 2.5 y/s 8. Constant speed 9. Coming back & Constant speed 10. Stopped 11. Speed Decreasing 12. Albert 13. Charlie 14. 5 seconds 15. 14 seconds 16. 100 m/12 s = 8.33 m/s 17. Accelerating 18. Slowing down 19. Constant speed 20. Stopped 21. Accelerating 22. Constant speed 23. Decelerating 24. At rest 25. Accelerating
  • Slide 9
  • Balanced forces - equal forces acting in opposite directions balance each other; they will not change the objects motion; net force = zero Unbalanced forces - cause an object to start moving, stop moving, or change direction 100 N 60 N Net force is 40 Newtons to the right Net force
  • Slide 10
  • Slide 11
  • Ground Gravity Applied Force Rolling Friction
  • Slide 12
  • True or False? More than one force can act on an object at once. TRUE. Forces that act in opposite directions combine (add) together. FALSE. In this case the two forces would act against each other. To find the net (total) force on an object you should add all the forces on an object together? FALSE. The strength of the net force is the difference between forces acting in opposite directions, and the combination of forces acting in the same direction.
  • Slide 13
  • Bellwork- Thursday 12/7/11 A skydiver falls faster and faster through the air. Eventually her velocity will a) increase b) decrease c) remain constant How can you explain this? Terminal velocity- maximum (constant) velocity a falling object reaches; no longer accelerating; air resistance = gravity A cowboy drops his gun while riding his horse at a fast gallop. In the absence of air resistance, where will the gun hit the ground relative to the horse? a. In front of the horse b. Behind the horse c. Next to the horse Why? Gravity pulls gun down, but it will also continue to move straight forward with the same velocity as the horse (inertia- 1 st law of motion). There is no air to push it any other way.
  • Slide 14
  • One person pushes a book with a force of 20 Newtons left. The other person pushes the book with a force of 18 Newtons right. Are these forces balanced or unbalanced? Would these forces cause the object to move? If so, in which direction? How can you tell? What is the net force? Unbalanced The object moves left. The magnitude of the arrow pointing left is greater. 20 N 18 N = 2 Newtons Net Force = 2 N 20 N 18 N 4.7- TSW IDENTIFY THE FORCES ACTING ON MOVING AND STATIONARY OBJECTS.
  • Slide 15
  • Two people push on the book with the same strength (one 20 N left, and the other 20 N right). Are these forces balanced or unbalanced? Would these forces cause the object to move? If so, in which direction? How can you tell? What is the net force? Balanced The object would not change its motion. The magnitude of both arrows are equal, in opposite directions. 20 N 20 N = 0 Newtons In this case the two forces would exactly cancel each other out. Net Force = 0 N 20 N
  • Slide 16
  • Two people push a book in the same direction. One person pushes to the right with a force of 8 Newtons; the other person pushes to the right with a force of 6 Newtons. Are these forces balanced or unbalanced? Would these forces cause the object to move? If so, in which direction? How can you tell? What is the net force? Unbalanced The object moves right. The arrows in the same direction, so they combine/add together. 6 N + 8 N = 14 Newtons Net Force = 14 N 8 N 6 N
  • Slide 17
  • 4.8- TSW DETERMINE THE NET FORCE ON AN OBJECT, GIVEN A DIAGRAM. Combine the forces to find the net force in the appropriate direction.
  • Slide 18
  • 4.8- TSW DETERMINE THE NET FORCE ON AN OBJECT, GIVEN A DIAGRAM. The arrows below show forces acting on an object. Use the diagram to answer the following question. What is the net force on the object and in what direction would the object move? What action would be necessary to balance the forces? Add a force of 50 N to the right and add 25 N downward. Subtract 25 N downward and add 25 N upward. Add a force of 50 N to the right and subtract 25 N downward. Subtract 25 N to the right and subtract 25 N downward. 100 N
  • Slide 19
  • A force of 100 N is applied to the right on the wooden crate, and a force of 250 N is applied to the left, draw a force diagram. What is the affect of the forces on the wooden crate? a) The box moves straight up. b) The box moves to the right. c) The box moves to the left. d) The box does not move. What is the net force? 150 N, left A bus is driving and has an applied force to the right of 1000 N. As it approaches a bus stop, the brakes apply a friction force of 1000 N to the left. Draw a force diagram. Will the force stop the bus, or will the kids get left there? Why/why not? No! Balanced forces = constant speed = kids will get left there! 100 N250 N 1000 N
  • Slide 20
  • Force (Free-Body) Diagrams- pg 14 Free-body diagrams - used to show the size (magnitude) and direction of all forces acting upon an object in a given situation The object is normally drawn as a square, with the forces all pointing outwards from the center. Shown is an example of a free body diagram. Notice the arrows are drawn and labeled to indicate the force they represent. What do they mean? F frict Force of friction F grav Force of gravity F app Applied force F norm Normal force
  • Slide 21
  • F frict Friction Force The force exerted by a surface as an object moves across it or makes an effort to move across it; two types: kinetic (sliding, rolling, fluid) and static friction F grav Gravity Force Directed "downward" towards the center of the earth F app Applied Force Force which is applied to an object by a person or another object F norm Normal Force Support force - exerted upon an object which is in contact with a stable object F net Net force Sum of all the forces acting on an object; in the direction the object moves When net force = 0, there is no movement/no change in motion F air Air Resistance Force Fluid Friction- This force will frequently be neglected due to its small size; It is most noticeable for objects which travel at high speeds
  • Slide 22
  • Find the net force by finding the sum of the forces acting on the object. 400 N 200 N 20 N 5 N 0 N 15 N 0 N
  • Slide 23
  • Calculate the missing forces that yield the expected net force. A = 50 N (the horizontal forces must be balanced) B = 200 N (the vertical forces must be balanced) C = 1100 N (in order to have a net force of 900 N, up) D = 20 N (in order to have a net force of 60 N, left) E = 300 N (the vertical forces must be balanced) F = H = any number you wish (as long as F equals H) G = 50 N (in order to have a net force of 30 N, right)
  • Slide 24
  • Free Body Diagrams A vase is at rest on a table top. Diagram the forces (2) acting on the vase. An egg is free-falling from a nest in a tree. Neglect air resistance. Diagram the force (1) acting on the egg as it is falling.
  • Slide 25
  • A flying squirrel is gliding from a tree to the ground at constant velocity. Consider air resistance. Diagram the forces (2) acting on the squirrel. A car is coasting to the right and slowing down. Neglect air resistance. Diagram the forces (3) acting upon the car.
  • Slide 26
  • A skydiver is descending with a constant velocity. Consider air resistance. Diagram the forces (2) acting upon the skydiver. A force is applied to the right to drag a sled across loosely-packed snow with a rightward acceleration. Neglect air resistance. Diagram the forces (4) acting upon the sled.
  • Slide 27
  • A rightward force is applied to a book in order to move it across a desk at constant velocity. Consider frictional forces. Neglect air resistance. Diagram the forces (4) acting on the book. A rightward force is applied to a book in order to move it across a desk with a rightward acceleration. Consider frictional forces. Neglect air resistance. Diagram the forces (4) acting on the book.
  • Slide 28
  • A lacrosse ball is moving upwards towards its peak after having been cleared by the goalie. Neglect air resistance. Diagram the force (1) acting upon the lacrosse ball as it rises upward towards its peak.
  • Slide 29
  • TURN IN PACKET 8!! You wont be needing it for a few days
  • Slide 30
  • Bell Work: Monday 12/12/11 Get Packet 9 off front table. Read pages 10, 11, and 12 SILENTLY. Per. 1, 2, 3: Make sure you turned in Bell Work from last week Per. 1, 2, 3, 5, 6: Make sure Packet 8 is turned in.
  • Slide 31
  • Brake It, But Dont Break It- Packet 9, Page 10 Purpose: To use Newtons laws of Motion to design a ramp that can transport fragile materials safely Background: Background: You and your partners are industrial engineers working at a glass company. At the warehouse, cartons of fragile glassware are stored in a loft above the ground floor. The president of the company has given you the job of designing a ramp for carts to carry boxes of glassware down to the main floor. The ramp must fit in a relatively small area and get the glass down quickly, but without breaking. It will take too long to wrap each glass with protective padding or to fasten the boxes down. Speed alone must provide the margin of safety.
  • Slide 32
  • Data TablesShifting Units ONLY CHANGE ONE VARIABLE IN EACH EXPERIMENT Task 1: Ramp Height Task 2: Starting Position Count how far the washer shifted when it has finally stopped. Moving forward = positive Moving backwards = negative No motion = O; Flies off = OFF Brake It, But Dont Break It- Pg 10 Team Roles Work with tables for final project. Look at the letter or number on the bottom of your car so you use the same one tomorrow! Roles: changing height (books), measuring ramp starting position, measuring distance rolled, retrieving car, measuring shifting units, recording data. Each group should stay in their own space during the entire class period.
  • Slide 33
  • Bellwork: Tuesday 12/13/11 Where do we find each type of friction in Brake it, But dont Break it? Sliding Friction Between the washers and the cart (if there are shifting units) Rolling Friction Between the wheels and the ramp as the cart rolls Fluid Friction Between the air and the cart as it rolls
  • Slide 34
  • Rules For Final Challenge You will have 25 min to construct your best ramp. You will use 10 washers on your car. The car must slide down the ramp wheels side down The washer(s) will be stacked in the center of the car, and cannot be attached to the car or to each other. No stopping materials may be attached to the car, but may be attached to the ramp.
  • Slide 35
  • Thursday: Brake It, But Dont Break It- Final Challenge Finish Task 1 & 2 Ways to earn points, and earn the contract for ramp building with the glass company! Highest ramp height Highest starting position Stop in shortest distance Washers dont fall off Ramp is successful on 1 st try You must call me over today to grade your final challenge!
  • Slide 36
  • Pkt 8, Pg 15- Momentum ( p ) = mass * velocity Units = mass (kg) * velocity (m/s) = kg*m/s All objects in motion have momentum The more momentum an object has, the harder it is to stop Like velocity and acceleration, described by a direction also Can a small mass produce a large momentum? Of course! If so, can you think of an example? A bullet shot from a gun What makes it have such a large momentum? It has a small mass, but it has a very large velocity
  • Slide 37
  • Law of Conservation of Momentum The total momentum of objects in an interaction does not change, unless outside forces act on the object The quantity of the momentum is the same before and after objects interact
  • Slide 38
  • Uniform motion around a circle Is motion around a circle accelerated motion? Why or why not? YES. By Newton's First Law, any motion not in a straight line is accelerated, and requires a force to maintain. Acceleration is a change in speed or direction
  • Slide 39
  • The force of gravity is at all times directed downwards and the normal force is at all times directed perpendicular to the seat of the car.
  • Slide 40
  • Centripetal Force- center seeking; push or pull on a moving object directed towards the center of its curved path. Centrifugal Force- center fleeing; push or pull on moving object directed outwards from the center of the curved path. Newtons 3 rd Law- Centripetal and Centrifugal forces are an action-reaction pair. They are equal in magnitude, but opposite in direction. Centripetal Force Back To Forces and Motion Centripetal Force = The push or pull on a moving object toward the center of its curved path. Centripetal force is always a net force.net force Back To Forces and Motion Centrifugal Force DRAW THIS DIAGRAM Draw and label arrows
  • Slide 41
  • Give It a Whirl- Pkt 9, pg 13 Exploring Circular Motion & Whirling Rides You work for an amusement park ride design company. The company has asked you to design a new whirling ride that demonstrates centripetal force and G force, and wants you to submit your ride concept in the form of a diagram. You will experiment with a ride that has a seat attached to the end of a cable. The cable and seat should be able to extend outward as the ride revolves faster and faster. Incorporate this experiment into your new and different thrill ride.
  • Slide 42
  • Measuring Motion in a Circle Radius, Diameter, Circumference Radius: distance from center to the circles edge RPMs ( R evolutions P er M inute): the number of times an object moves in a complete circle (along the circumference) around a stationary center, in one minute Note: Your trials are only 30 seconds each Find average. Multiple average by 2. This is your Average RPMs
  • Slide 43
  • Procedures: Give it a Whirl Variables Roles Tips: 1. Practice your twirling techniques 1. Hold ring not string!! 2. Finish the trials for as many trials as possible (test how changing radius affects the RPMs) Trial an instance of testing as part of a series of tests or experiments **Demo of trial** Twirler Counter Timer Recorder 1. Radius 2. Number of Gs Twirler- NO! the same person must twirl for every trial, both days Variables
  • Slide 44
  • Bellwork- Tuesday 2/1/2011 1. Sketch the diagrams then label the arrows to show the forces. Rotating Drum Ride (top view)Turning a Corner Rollercoaster Loop Centripetal Force Centripetal Force Centrifugal Force Centrifugal Force Centrifugal Force Inertia 2. Define centripetal force, centrifugal force, and inertia. Centripetal force- center seeking force in circular motion Centrifugal force- center fleeing force in circular motion Inertia- tendency of an object to resist a change in its motion Centripetal Force
  • Slide 45
  • You attach a string to a ball and swing it in a circular motion. What force is required to keep the ball moving in a circular path? Centripetal force- required to keep the ball moving in the circular path; directed towards center
  • Slide 46
  • Give It a Whirl (Day 2): Divide groups into 4 roles, again. All students with roles OTHER THAN twirler, may change roles today. 1. Twirler 2. Counter 3. Timer 4. Recorder To keep the experiment valid, only one variable may changechanging the twirler (since all people twirl differently) would be changing too much! Task for today: Finish all trials (radius and Gs) Angle Sketching Task for today: Finish all trials (radius and Gs) Angle Sketching
  • Slide 47
  • Bellwork: Wednesday 2/2/2011 Sketch a top view of the Give it a Whirl apparatus Label the forces that occur: Inertia, centripetal force, centrifugal force, gravitational force, net force. Gravitational force Centripetal force Inertia Net Force Centrifugal force
  • Slide 48
  • When Finished with GIAW Lab Finish graphs Conclusion questions Create new spinning ride! detailed, colored, labeled with forces
  • Slide 49
  • Bellwork: Thursday 1/13/2011 2. What is the net force on the skydiver in B, C, and D? (include magnitude and direction). B = 833 N 350 N = 483 N down C = 833 N 700 N = 133 N down D = 833 N 833 N = 0 N (balanced) 3. What do we call the velocity of the skydiver in Diagram D? Explain. Terminal velocity ; Air resistance = gravity 4. If the plane was up 1,243 m when the 93 kg skydiver jumped, what was his max PE? PE = mgh = 93 * 9.8 * 1243 = 1,132,870.2 J 5. He reached a maximum velocity of 55.56 m/s (124 mph). What was his max KE? KE = mv 2 = (93) * (55.56) 2 = 143,541.4 J 6. ACC: How much energy did he lose to air friction? 1,132,870.2 J - 143,541.4 J = 989,328.8 J 1. What kind of friction is the skydiver experiencing? Fluid Friction
  • Slide 50
  • Swing of Things: Pendulum Ride- pg 6
  • Slide 51
  • Swing of Things Period- the time for a cycle to pass the observer Amplitude- the maximum angle reached by the pendulum; amount displaced from resting position Think back to the Waves Unit!!
  • Slide 52
  • LENGTH AMPLITUDE Measure with centimeters, not inches Dont cut the string Roll/unroll around the pencil to make it shorter/longer 70cm & 80cm: Use chair/binder/textbooks to lift pendulum so it does not drag on the ground Use the protractor Remember, measure from the resting position, outwards HOLD THE WASHER, NOT THE STRING WHEN MEASURING AMPLITUDE Each trial is timed, so there is no way to RUSH through them. You must finish all 23 trials TODAY. Use your cell phone stopwatch if you want.
  • Slide 53
  • If each colored line represents a different amplitude of the pendulum, what is the amplitude (angle from rest- black) of each color. ORANGE BLUE GREEN PINK??? 13-14 37-38 43-44 63-64
  • Slide 54
  • 10 mins- Finish Swing of Things: Pendulum Ride- pg 6
  • Slide 55
  • How much potential energy does the 45 kg skateboarder to the left have if he is 2 meters above the edge of a 18 meter tall half pipe? PE = mgh PE = 45*9.8*20 PE = 8820 J What is his velocity at the peak of his turn (shown left)? 0 m/s What is the KE at the peak? KE = mv 2 KE = * (45) * 0 2 KE = 0 J Bellwork: Friday 1/14/2011
  • Slide 56
  • What type of energy does a bike rider have when they are standing at the top of the half pipe? Gravitational Potential Energy- stored energy due to height as they roll down the ramp? Kinetic Energy- energy of motion
  • Slide 57
  • Semester One Final Exam Study Guide Due Thursday: Pages 1 & 2 Due Friday: Pages 3 & 4 Due Monday: Pages 5 & 6
  • Slide 58
  • Semester Exam Study Guide Use a highlighter to mark the number of all the questions your partner did not finish Work on study guide for the rest of the period! Finish blank questions Quiz each other Go over correct answers to check each other Make sure OOPS Passes are turned in!
  • Slide 59
  • Monday 1/24/2011 Day to work with group on Thrill Ride! Project DUE: February 10, 2011 Model Brochure Presentation Participation End of the Day Reflection
  • Slide 60
  • Bellwork: Tuesday 1/25/2011 1. Draw the ramps. Label where a cart would have max PE and max KE. 2. Starting the same cart from the top of each ramp, which ramp (pink, green, teal) would provide the cart with the most PE? Why? Each ramp would provide the same amount of PE. PE= mgh and the height of each ramp is the same. 3. What would happen to the washers if the cart ran into a barrier? They would fly forward and off of the cart. What law of motion predicts this will happen? Explain. Newtons First Law the Law of Inertia: The washers are moving forward on the cart and will continue moving with the same velocity (speed and direction) even if the cart hits a barrier. MAX PE MAX KE
  • Slide 61
  • 10 mins- Finish Swing of Things: Pendulum Ride- pg 6
  • Slide 62
  • Bellwork- Wednesday 1/26/2011 1. State the formula for Newtons 2 nd Law of Motion. Force = mass * acceleration 2. A carts mass is 0.85 kg. What force would you have to apply to the cart if you want to accelerate it 2 m/s 2 ? Force = mass * acceleration; F = 0.85 * 2 = 1.7 N 3. If you apply a force of 5 N to the same cart (0.85 kg), what will be the resulting acceleration? Acceleration = force/mass; A= 5/0.85 = 5.88 m/s 2 4. You add washers to the cart to increase its mass. You apply a force of 5 N to the cart, and it accelerates 2.7 m/s 2, what was the mass of the cart? Mass = force/acceleration; M = 5/2.7 = 1.85 kg How much mass did you add? 1.85 0.85 = 1 kg of washers
  • Slide 63
  • Friday 1/28/2011: Brake It, But Dont Break It- Final Challenge Ways to earn points, and earn the contract for ramp building with the glass company! Highest ramp height Highest starting position Stop in shortest distance Washers dont fall off Ramp is successful on 1 st try You must call me over today to grade your final challenge! Work on final project when done
  • Slide 64
  • Thrill Ride! Final Project Packet What are your responsibilities over the next weeks? Split up sections of the rubric? Construct part of the ride? Working on this project the entire week Keep in mind the themes for the different parts of Sir Isaacs Inertialand! Your plans will be reviewed by Ms. Saunders. 1. Fairness Survey- turn in daily Group Representative- new daily 2. End of the Day Evaluation- turn in daily Everyone must individually fill out their portion
  • Slide 65
  • 1). Label the positions where a child would have Potential energy (PE) and Kinetic energy (KE) 2). Describe the energy transformations 3). Show arrows for any other forces contributing to the motion of the playground equipment (gravity, friction) Bellwork- Monday 1/31/2011 PLAYGROUND PHYSICS Sketch two types of playground equipment (slide, swing, see saw, climbing equipment, etc.) Slide- PE at top converts to KE when sliding to bottom Other: gravity and friction Swing- Approaching the high point of the swing = more and more KE gets stored as PE. Top- all PE, swinger stops moving Other: gravity, pumping your legs adds energy See-saw- High point has max PE grav ; Falling to ground PE converts to KE Other: gravity, friction (air resistance)
  • Slide 66
  • Bellwork: Thursday 2/3/2011 RideAccidents.com Read the passages. These are real accidents, and real examples of how what we have been learning about can be dangerous and deadly. How do Newtons Three Laws of Motion, forces, or other principles of physics explain the cause of each accident? 1. Identify 2 scenarios describe how each relates to class. i.e. Woman-Ferris wheel: Without gravity and inertia (1 st law of motion), this could not have happened. 2. Brainstorm 4 ways you can make the ride YOU design much safer, using these situations and what you now know.
  • Slide 67
  • Pink Bellwork Quiz- ONLINE @ Home Due FRIDAY or MONDAY Copy Diagrams from small sheet to use on QUIZ
  • Slide 68
  • Thrill Ride! Final Project Packet Review expectations and guidelines for project Yellow sheet- Work in groups to brainstorm, fill out, and make plans. What are your responsibilities over the next week? Split up sections of the rubric? Construct part of the ride? Working on this project the entire upcoming week Keep in mind the themes for the different parts of Sir Isaacs Inertialand! Your plans will be reviewed by Ms. Saunders. 1. Group IDs 2. End of the Day Evaluation- turn in daily Everyone must individually fill out their portion
  • Slide 69
  • Bellwork: Friday 2/4/2011- G Forces 1. Why do I feel heavy at the bottom of hills? 2. Why am I raised off the seat sometimes? 3. What throws me to the side of the car on some parts of the ride? 4. What throws me backwards on some rides? 1. Heavy? Positive Gs Max on coaster= 5Gs (on a jet ~9Gs- special G suit) 2. Lifted off seat? Negative Gs Below 1 G is negative. Weightless? Zero Gs 3. Thrown to side? Lateral Gs when turning a corner NOTE: One G is the pull of normal gravity. Currently, we are all at one G. 4. Thrown backwards? Linear Gs
  • Slide 70
  • Thrill Ride! Final Project Packet Review expectations and guidelines for project Yellow sheet- Work in groups to brainstorm, fill out, and make plans. What are your responsibilities over the next week? Split up sections of the rubric? Construct part of the ride? Working on this project the entire upcoming week Keep in mind the themes for the different parts of Sir Isaacs Inertialand! Your plans will be reviewed by Ms. Saunders. 1. Group IDs 2. End of the Day Evaluation- turn in daily Everyone must individually fill out their portion
  • Slide 71
  • Bellwork: Monday 2/7/2011 Find the momentum for each situation. Which has more momentum? Momentum = mass * velocity A 3 kg sledgehammer swung at 1.5 m/s 3 kg * 1.5 m/s = 4.5 kg*m/s A 4 kg sledgehammer swung at 0.9 m/s 4 kg * 0.9 m/s = 3.6 kg*m/s Show your work to calculate both scenarios!
  • Slide 72
  • Thrill Ride! Final Project Packet Watch video of past presentation Hand out presentation assignment guides Fill in presentation guide Your plans will be reviewed by Ms. Saunders. End of the Day Evaluation- turn in daily Everyone must individually fill out their portion
  • Slide 73
  • Review Conclusion Questions- pg 19 Newtons Three Laws of Motion: Review Newtons First Law: Law of Inertia- Objects in motion tend to stay in motion and objects at rest tend to stay at rest unless acted upon by an outside, unbalanced force. Newtons Second Law: Force equals mass times acceleration (F = ma). Newtons Third Law: Pairs of Forces- For every action there is an equal and opposite reaction.
  • Slide 74
  • Bellwork: The more massive the object, the stronger the gravitational pull on other objects True The farther the objects are from each other, the stronger the gravitational pull False. The closer the objects are together, the stronger the gravitational pull.
  • Slide 75
  • Bellwork- Tuesday 12/15/2011 Sketch the diagram below. 1. The PE at the top is 50 J, what is the potential energy at positions A, B, C, D, E, F shown on the stair steps and the incline? 2. Can you tell how much KE is at the bottom? Why or why not? (Hint: Law of Conservation of Energy- Is the ball losing energy to anything on the way down?) 3. What type of friction is the ball undergoing as it is falling? As it is going down the slide? 1. A: 40 J B: 30 JC: 20 J D: 10 J E: 0 JF: 0 J 2. KE is less than 50 J at the bottom- some is lost to friction (Kinetic energy thermal energy) Energy is not created or destroyed only transformed to other types 3. Falling- Fluid friction Slide- Rolling friction
  • Slide 76
  • Review Interim Essay Question A child rolls a marble down the ramp as shown below. The marble travels across surface B at a constant speed, then starts to go up the incline of surface C. A. After the marble is released, state whether the forces are balanced or unbalanced while on surface A. Unbalanced B. Using appropriate vocabulary, describe the motion of the marble while it is traveling down surface A. Accelerating, speeding up, increasing velocity C. State the motion of the marble as it is traveling across surface B, and support your statement with evidence. The forces are balanced because its traveling at a constant speed. D. State the motion of the marble as it is traveling up surface C, and support your statement with evidence. The forces are unbalanced, so it is decelerating, slowing down, decreasing velocity
  • Slide 77
  • Gravity- Mass and Distance Practice Problems If each of the objects is identical, in which case is the gravitational force the LEAST? 4.0 cm 3.5 cm 3.0 cm 2.5 cm As a satellite falls toward Earth, the gravitational force between the satellite and the Earth increases. Which statement best explains why there is an increase? As the satellite approaches Earth, the satellite rotates faster The mass of the satellite increases as it nears earth The distance between Earth and the satellite decreases
  • Slide 78
  • Gravity- Mass and Distance Practice Problems The amount of gravitational attraction between the Moon and an astronaut standing on its surface depends on the astronauts distance from the center of the Moon and the astronauts Height Mass Shape Weight Which of these would result in the LEAST gravitational attraction? Two 2 g objects, 2 meters apart Two 2 g objects, 4 meters apart Two 1 g objects, 6 meters apart Two 1 g objects, 8 meters apart
  • Slide 79
  • Two guys are pulling on a rope. One pulls to the right with a force of 700 N. The other pulls to the left with a force of 500 N. What is the net force (magnitude and direction)? 200 N, right A girl is playing pool, and is about to use the cue (white) ball to hit the 8 ball into the corner pocket. Which diagram shows the force she should apply to accelerate the cue ball? 500 N 700 N
  • Slide 80
  • Potential and Kinetic Energy Homework- pkt 8, pg 13 Energy Basics 1. Potential 2. Kinetic 3. Kinetic 4. Potential 5. Potential 6. Kinetic 7. Kinetic 8. Kinetic (and/or Potential) 9. Potential (and/or Kinetic) 10. Potential 11. Potential 12. Potential 13. Kinetic (and/or Potential) What is energy? 1. Potential 2. Kinetic 3. Kinetic 4. Potential 5. Potential 6. Kinetic 7. Potential 8. Highest KE- C (bottom); Lowest KE- A (top) 9. Highest PE- A (top); Lowest PE- C (bottom) 10. 50 * 9.8 * 3 = 1470 J 11. Friction with the slide/air; child pushing off, etc. 12. Rollercoaster, jumping on a trampoline, etc. 27 pts
  • Slide 81
  • Bellwork: Wednesday 1/6/2011 1. Where is the maximum PE? A, B, C? 2. What type of PE does the boy have? 3. Where is the maximum KE? A, B, C? 4. What is the maximum PE of the boy? (Hint: You need to use a formula to answer this!!) 5. What is the maximum KE of the boy, if his velocity is 2 m/s? (Hint: You need to use a formula to answer this!!) 1. A 2. Gravitational Potential Energy 3. B 4. PE grav = mgh PE grav = 1960 Joules 5. KE = mv 2 KE = 40 Joules Acceleration due to gravity = 9.8 m/s 2 Mass of the boy = 20 kg
  • Slide 82
  • Monday 1/11/10 OOPS passes/mini earths- collecting today Otherwise bring on your exam day Exam Review Packet- Pages 5 & 6 Bring on your exam day I will give credit for it on this day Jeopardy Review to Study Extra Credit opportunity
  • Slide 83
  • Bellwork- 1.Which path will the ball follow? (Letter; and Draw it) 2.Which Law of Motion explains this? 3.Draw arrows and label the following forces on the diagram you choose: gravity, inertia, net force 1.Which path will the ball follow? (Letter; and Draw it) 2.Which Law of Motion explains this? 3.Draw arrows and label the following forces on the diagram you choose: gravity, inertia, net force Draw this diagram. When the ball at the end of the string swings to its lowest point, the string is cut by a sharp razor.
  • Slide 84
  • Bellwork- Friday 12/18/2011 a. The elephant will stop first due to its larger mass. b. The ant will stop first due to its smaller mass. c. The elephant and ant will stop at the same time. d. The elephant and ant will not stop and will continue at 1 meter per second as long as the ice lasts. Newtons First Law of Motion- Inertia!! Suppose an elephant and an ant are both running at 1 meter per second when they both encounter a long patch of slick, frictionless ice. They begin to slide on the ice. Which of the following statements is true concerning their motion? Which law of motion supports this answer?
  • Slide 85
  • Identifying the relationship between Kinetic and Potential Energy How do the meters show the relationship between the amount of Kinetic Energy (KE) the car has, and the amount of Potential Energy (PE) the car has? As the amount of PE decreases, the amount of KE increases, and vice versa.
  • Slide 86
  • Thrill Ride!! Indestructible Energy (Pkt 8, pg. 11) Paragraph 2 Define the Law of the Conservation of Energy. Energy cannot be created or destroyed, only transformed from one form to another Relate the amount of energy at the end of an event to the amount at the beginning of the event. Equal to each other Paragraph 3 If you were building a roller coaster, which hill would you make the largest? Why? The first hill. The potential energy of the first hill defines how much energy the rest of the ride has to work with. What would happen if you made the second hill taller than the first hill? The ride would not make it to the top of the second hill. Paragraph 4 What are the two new forms of energy we see here? Heat (thermal) energy and mechanical energy (ME = PE + KE) What causes the warming of the track? Friction So, did we destroy the energy? What happened? No, energy is never destroyed, an energy transformation takes place.
  • Slide 87
  • Thrill Ride!! Indestructible Energy (pg. 17) Paragraph 5 What is a vehicle that has a lot of friction with the air? Hummer, semi-truck, UPS delivery truck What is a vehicle that does not have a lot of friction with the air? (probably your dream car!) Think in terms of air resistance. Corvette, Lamborghini Paragraph 6- Important! In three words, what is kinetic energy? energy of motion In two words, what is potential energy? stored energy
  • Slide 88
  • Thrill Ride!! Indestructible Energy (pg. 17) Paragraph 7 (3x) Give an example of potential energy. How do we know it has potential energy (or, what does it have the potential to do)? Stretched rubber band- Potential to snap Water at the top of a water fall- Potential to fall Gas in a car- Potential to make the car move (3x) When does the energy change to kinetic energy? When the rubber band is moving/snapping When the water is falling When the car is driving/moving Paragraph 8 What is the relationship between kinetic and potential energy throughout a ride? P.E. and K.E. are transformed/converted from one form into the next as a car moves up and down the hills Paragraph 9 Why does the reading say if you apply the brakes long enough the ride will come to a stop? Because the length of time the friction is applied, also influences the force Paragraph 10 Why do we need mechanical energy? To pull the car up the incline, this is the initial energy needed.
  • Slide 89
  • Due to the cars greater mass, it has more MOMENTUM. The more momentum an object has, the harder it is to stop. Bellwork: Tuesday 11/25/08 You can catch a baseball moving at 20 m/s, but you cant stop a car moving at the same speed. Why? Put your PINK Humpty Dumpty Lab on your table to be collected.
  • Slide 90
  • Review of Concepts- Notes What did you learn that you can apply to designing/building an amusement park ride? Give it a Whirl- Roller Derby- Brake It, But Dont Break It-
  • Slide 91
  • Test Corrections # of question wrong A. Question B. Wrong answer- why you chose it C. Correct answer- how you know this is correct # 25 A.Which wave is high pitched, low pitched? loud, or quiet? B.I said A was high pitched and loud, and B was low pitched and quiet. I thought that a smaller wave would be quieter and lower. C.A is low pitched and loud. B is high pitched and quiet. A large wavelength/low frequency means low pitched. A large amplitude means louder.
  • Slide 92
  • Bellwork Tuesday 12/2/08 1. If a fire engine and a tricycle are rolling at a speed of 5 km/hr, which would be easier to stop? Why? 2. Can a bullet and an automobile have the same momentum? Explain how. 3. When a truck driver begins to brake, what happens to the momentum of the truck? Explain.
  • Slide 93
  • Bellwork: Thursday 12.11.2008 Lazy Coin Refer to the beaker, index card, and coin in the back of the room. 1. How can you move the coin into the cup without touching the coin, or holding the card? 2. What principle of physics or Law of Motion explains why this is possible? 1. When you flick the card, the lazy coin falls into the cup. 2. This is due Newtons First Law of Motion- The Law of Inertia. The coin remains where it is (at rest) even though the card is gone.
  • Slide 94
  • Draw free body diagrams to illustrate the forces on the coin and cup at different parts of the journey. 1. Flicking the card to the left; card sliding (4) 2. Coin falling, accelerating downwards (2) 3. Coin hitting the ground (2) STUMPED? Forces to consider: F app - flicking the cup F grav - pulling the coin into the cup F frict - sliding friction between coin and card F air - air resistance between falling coin and bottom of the cup F norm - card pushing up or cup bottom pushing up
  • Slide 95
  • Bellwork: Friday 12/12/2008 Riding over a wet road, the wheels of a bike acquire a coating of water which soon flies off again. 1. In which direction does it fly off? 2. What principle of physics explains why this happens? 3. Draw a diagram of the wheel and water, showing what you would see. 1. It will fly backwards and upwards from the rim of the wheel. This is why truckers hang mudguards behind their wheels. 2. 1 st Law of Motion Inertia 3.
  • Slide 96
  • Tasks for Today Guided Notes: Brochure ALL members of the group should have one Group Goal Setting End of the Day Reflection- turn in daily Fairness Survey- turn in daily Group Representative- new daily Take a moment to grade your teammates. How well did you work together? Answer all questions completely and honestly. LAST DAY in the computer lab! Make effective use of your time! After break- In class work on Monday, Tuesday, and Wednesday FINAL brochure, FINAL ride, FINAL presentation must all be ready by Thursday after break!!!!!
  • Slide 97
  • The LAST DAY for any make up workincluding any past labs, quizzes, etc... Tuesday, January 6 th NO EXCEPTIONS!!!!!!
  • Slide 98
  • Bellwork: Friday 12/19/2008 What Law of Motion am I talking about? 1. The book on the car dashboard slides off and falls into your lap when the light turns green, and the car starts to move? 1 st Law of Motion If the object was sitting still, it will remain stationary. 2. Why you have to wear a seatbelt? (besides for, Its the law!) 1 st Law of Motion If it was moving at a constant velocity, it will keep moving. Basically, an object will keep doing what it was doing unless acted on by an unbalanced force.
  • Slide 99
  • Monday 1/5/2011 Final Project Work in groups on brainstorming, filling out yellow sheet, and making goals/plans for this week. Guided Notes: Brochure ALL members of the group should have one Group Goal Setting End of the Day Reflection- turn in daily Fairness Survey- turn in daily What are your responsibilities over the next 3 days? Split up sections of the rubric? Construct part of the ride? Type part of the brochure? Monday- In class work Tuesday- In class work; LAST DAY for any make up workpast labs, quizzes, etc... Wednesday- In class work Thursday- FINAL brochure, FINAL ride, FINAL presentation DUE Friday- 6 th and 7 th grade presentations
  • Slide 100
  • Tuesday 1/6/2011 Final Project Group Goal Setting End of the Day Reflection- turn in daily Fairness Survey- turn in daily What are your responsibilities over the next 2 days? Split up sections of the rubric? Construct part of the ride? Type part of the brochure? Notes: A marble can serve as the rider on your ride Look at pictures of rides from last year Tuesday- In class work; LAST DAY for any make up workpast labs, quizzes, etc... Wednesday- In class work Thursday- FORMAL FINAL brochure, FINAL ride, FINAL presentation DUE Friday- INFORMAL 6 th and 7 th grade presentations
  • Slide 101
  • Wednesday 1/7/2011 Final Project Group Goal Setting End of the Day Reflection- turn in daily Fairness Survey- turn in daily What are your responsibilities over the next day? INTENTIONAL DRESS TOMORROW Formal or Theme NEW FOR TODAY: Review Guide for Final Exam Exams next W, Th, F Final Essay Question See end of the class on Monday Write beginning of class on Tuesday Wednesday- In class work Thursday- FORMAL FINAL brochure, FINAL ride, FINAL presentation DUE Friday- INFORMAL 6 th and 7 th grade presentations
  • Slide 102
  • Thursday 1/8/2011 Oral Presentation role assignments--Exact specifications for presentation TODAY 3-5 mins long- NO LONGER Conclusion Do not read directly from brochure Prepare for your presentation by giving your speech one time through with your group, making sure that every individual knows what they will be saying, and practicing good eye contact, clear and loud voices, and positive body language.
  • Slide 103
  • Review proper presentation etiquette Be a good listener by not talking while other groups are presenting Give each group your undivided attention Clap when each group is finished Write down two things you think each group did well and one thing that they could improve upon for Fridays Fair
  • Slide 104
  • Bellwork: Monday 1/12/09 A snowball stays on the porch railing all day long until someone picks it up and throws it. That same snowball will stay in motion until it is acted upon by a target of some sort, like a tree. >. At that time, it will stop immediately because the tree exerted a force on it. Describe the day in the life of the snowball in terms of forces, motion, and Laws of Motion. Be specific in defining the parts of the snowballs journey: 1. On railing 2. Moving through air 3. Hitting Tree
  • Slide 105
  • Classroom Business PROJECT: Please take home your Amusement Park Ride by Tuesday Tuesday after school rides will be disassembled and thrown away Grades for Participation, Model, and Presentation will be on Parentlink tonight EXAM: We will play Jeopardy Review Monday and Tuesday If you need to take your Science binder home to work on your study guide, feel free to do so I will stay afterschool on Monday and Tuesday if you need help on any of the study guide questions. FINAL GRADES: I am collecting OOPs Passes and Mini-Earths tomorrow for extra credit to be added to this quarter. OOPs Passes will automatically be added If you submit Mini-Earths they will all automatically be added to the 2 nd quarter grade unless you note otherwise
  • Slide 106
  • Bellwork 1/13/09 Sketch and Label What types of waves are these? Transverse Longitudinal Label the different parts (A, B, C) with the following: Wavelength Amplitude Compression Rarefaction Crest Trough Normal/Rest Positon Crest Trough Normal/Rest Position Rarefaction Compression Wavelength Amplitude Transverse Longitudinal
  • Slide 107
  • Classroom Business PROJECT: Please take home your Amusement Park Ride by TODAY Tuesday after school rides will be disassembled and thrown away Grades for Participation, Model, and Presentation are on Parentlink EXAM: Final Exam Essay Today We will play Jeopardy Review today, Tuesday If you need to take your Science binder home to work on your study guide, feel free to do so I will stay afterschool today, Tuesday if you need help on any of the study guide questions. FINAL GRADES: I am collecting OOPs Passes and Mini-Earths TODAY for extra credit to be added to this quarter. OOPs Passes will automatically be added If you submit Mini-Earths they will all automatically be added to the 2 nd quarter grade unless you note otherwise
  • Slide 108
  • Project Reflection 1. How did you like the process of choosing groups? How could it have been made better? 2. Did you like the timing of the projectspanning Winter Break? Or would you have rather had it due before break? 3. How could your time have been more well-structured IN CLASS? 4. Any other comments about the Thrill Ride project?
  • Slide 109
  • Bellwork- 1/7/2008 Metric Ladder/Metric Conversions On board
  • Slide 110
  • Bellwork 1-8-2008 56.9 m = _______ cm Draw 3 boxes, then sketch the molecular arrangement of a solid, liquid, and gas : solidliquidgas
  • Slide 111
  • Review Procedures Group Goal Setting End of the Day Reflection- turn in Fairness Survey- turn in In class work today!! LAST DAY!! Oral Presentation role assignments--Exact specifications for presentation TODAY 3-5 mins long- NO LONGER Conclusion Do not read directly from brochure FINAL brochure, FINAL ride, FINAL presentation must all be ready by TOMORROW!!!!! Wear your professional dress/clothes tomorrow!
  • Slide 112
  • Final Exam Preparation Work quietly with a partner to complete the Final Exam study guide Tomorrow: Final Exam Essay Test Homework tonight: Prepare for Essay Test tomorrow
  • Slide 113
  • We have a ball of tissue sitting in the mouth of a bottle. When we blow the tissue, it flies out of the bottle instead of being pushed in. Why? When we blow at the tissue, most of the air goes around the tissue, hits the back of the bottle, and comes back out again (after bouncing off the back of the bottle). This pushes the tissue out of rather than into the bottle. We can make the tissue ball go into the bottle, by blowing right at it using a straw.
  • Slide 114
  • Roller Coasters: Wooden vs. Steel Steel- faster, higher, loops Fastest: Kingda Ka, 128 mph Wooden- psychological advantage-track sways few inches- feet Fastest: Son of the Beast, 78 mph
  • Slide 115
  • With remaining time When finished, read Discovery File: Newtons Laws, a Moving Experience (Thrill Ride!, page 23) before beginning to answer the questions in the Lab. Then, begin your homework for tonight: State Newtons Three Laws of Motion and give an example of each. Use Chapter 10 of your textbook or the Internet as your reference
  • Slide 116
  • Bellwork: 11/6/07 *Write on BLUE Worksheet!* I like physical science laws because they treat everyone fairly: White, Black, Asian, Hispanic, rich, poorall are treated without favoritism by science laws. The only people who are hurt by them are people who ignore them. If you believe in them, they work. If you don't believe in them, they still work. Name one difference between science laws and the laws of our country. If youve played basketball in a gym, you have noticed that beneath the backboard, behind the hoop, there is a padded wall. What principle of physics explains why this padding is necessary?
  • Slide 117
  • Bellwork 11/8/07 You are a copy writer for a company that sells skin care products. You have been asked to write a paragraph describing a new sunless tanning product that contains SPF15. However, in reviewing the product description from the lab that creates your companys products, you find that the SPF has not actually been added to the product yet. The lab technicians have been unable to find a way to combine the SPF with ingredients in the product that do not cause an allergic reaction in people with sensitive skin. They plan to continue working on this and hope to have a solution to the problem soon. But, your supervisor wants to begin selling the product now, before the solution has actually been found. Write a short paragraph describing the product for the companys Web page.
  • Slide 118
  • What is the name of the ride that you have created for your proposal to the president of the amusement park ride design company you work for? You are in a boat that is sinking in the middle of a lake. You attempt to save yourself and the boat by patching the hole, and throwing the water out of the boat using a bucket. What principal of physics explains why the way you move the bucket enables the water to empty from it? Which Law of Motion is this? (You would use the law of inertia to empty it. You set the bucket and water in motion, and then quickly pull the bucket back. The water, by the law of inertia, keeps going. This is the First Law of Motion, also called the Law of Inertia.)
  • Slide 119
  • What Law of Motion am I talking about? 1. Basically, an object will keep doing what it was doing unless acted on by an unbalanced force. 1 st Law of Motion 2. If the object was sitting still, it will remain stationary. If it was moving at a constant velocity, it will keep moving. 1 st Law of Motion 3. It takes force to change the motion of an object. 1 st Law of Motion
  • Slide 120
  • If a roller coaster car is displaced from ground level to the top of the first drop of a roller coaster ride, then a chain driven by a motor supplies the force to do the work on the car. When the work is done upon the object, that object gains energy. The energy acquired by the objects upon which work is done is known as mechanical energy. an object with mechanical energy is able to do work on another object.
  • Slide 121
  • Engineering at the Cutting Edge Roller Coasters - 4 of 8 Movement - Video Start 1m 53s
  • Slide 122
  • Put your Memo, Diagram, and Yellow Packet, pen/pencil on your desk Overview Peer Review Please take this seriously You will turn in YOUR OWN review with your memo and diagram on MONDAY! If you dont have anything ready todayit is considered LATE- 20% off If you are ready to turn yours in today, thats fine, but make sure you looked over the suggestions from your peer
  • Slide 123
  • Roller Derby Guidelines for filling in data table Top of slide must be 50cm off the ground One part of the slide must touch the ground before the rider goes into the cup Record data for ALL TRIALS! successful and unsuccessful Possible roles: Recorder (1-2 people) Measurer (1-2 people) - measure starting and ending height Builder, Mover, Adjuster (1-2 people) reposition the slide to make the rider/ball go in the cup
  • Slide 124
  • Roller Derby Refer to Roller Derby Activity Grading Rubric (on your table) Starting Height (Hs): at least 50cm off the ground One part of the slide must touch the ground before the rider goes into the cup Finishing Height (Hf): at least 10cm off the ground No one needs to hold the slide up for it to work Ball rolls successfully into the cup on the first try!! Bonus: 360 degree loop, hill, 180 degree turn, 90 degree turn CALL MS. SAUNDERS WHEN YOU ARE READY TO BE GRADED! Record data for ALL TRIALS! successful and unsuccessful Possible roles: Recorder (1-2 people) Measurer (1-2 people) - measure starting and ending height Builder, Mover, Adjuster (1-2 people) reposition the slide to make the rider/ball go in the cup
  • Slide 125
  • Bellwork 12-10-07 2. Remember the elephant & the ant on the frictionless ice, sliding forever? Now, 2 helpful Science 8 students decide to help them. The two students exert a force on the elephant of 1 N and a force on the ant of 1 N. Which of the following statements is true ? Why? (Hint: 2 nd Law of Motion) a. The elephant will stop first due to its larger mass. b. The ant will stop first due to its smaller mass. c. The elephant and ant will stop at the same time. d. The elephant and ant will not stop and will continue at 1 mile per hour as long as the ice lasts.