Freshman Physics 1 Force & Interaction
Day 1Agenda: ● Review of velocity,
acceleration & force● Vectors WS● Begin Defining Newton’s
Laws
New Unit➢ Interaction & Forces
Do Now:Go Formative-- “Intro To Forces”
Due Today Semester 1 ReflectionDue Next ClassVectors WS
Freshman Physics 2 Force & Interaction
Physics Review
Use your Physics Binder as a reference tool to define the terms below in your new Toolbox.
● Velocity
● Acceleration
● Force
● Interaction
Freshman Physics 3 Force & Interaction
Vectors Worksheet
● The world’s greatest super-villain
● A mathematical term represented by an arrow, with both a direction and magnitude… OH YEAH!
Vector:
Freshman Physics 4 Force & Interaction
Net Force and Equilibrium
● Net Force: The sum of all force vectors acting on an object
● Equilibrium: A system is in equilibrium if the forces are balanced. (FNet= 0 N)
Freshman Physics 5 Force & Interaction
Vectors Worksheet
Each square represents a force of ONE NEWTON.
Magnitude = 5 NDirection = Right
Example:
This vector shows a 5 N force to the right.
Finish Questions1 and 2
of Packet
Freshman Physics 6 Force & Interaction
Vector Addition● More than one force
can act on an object at the same time.
● The first vector has shows a force of 5 N to the right.
● The second vector has shows a force of 3 N to the right.
● The sum of these 2 vectors would be 8 N to the right.
FNET (Resultant)
Freshman Physics 7 Force & Interaction
Vector Addition● Forces acting in
opposite directions● The first vector has
shows a force of 5 N to the right.
● The second vector has shows a force of 3 N to the left. ● The sum of these 2
vectors would be 2 N to the right.
FNET (Resultant)
Freshman Physics 9 Force & Interaction
Newton’s Laws
Newton’s 1st Law:
Newton’s 2nd Law:
Newton’s 3rd Law: (not yet!)
Freshman Physics 11 Force & Interaction
Forces
FNet = 0
Constant Velocity
FNet ≠ 0
Speeding up Slowing down
Balanced Unbalanced
Objects in motion stay in motion.Objects at rest stay at rest
When there is an unbalanced force, things accelerate
FNet in direction of motion
FNet in opposite direction
as motionAt Rest Constant Motion
v = 0 v ≠ 0
Constant change in motion (acceleration)
Freshman Physics 12 Force & Interaction
Forces
FNet = 0
Constant Velocity
FNet ≠ 0
Speeding up Slowing down
Balanced Unbalanced
Objects in motion stay in motion.Objects at rest stay at rest
When there is an unbalanced force, things accelerate
FNet in direction of motion
FNet in opposite direction
as motionAt Rest Constant Motion
v = 0 v ≠ 0
Constant change in motion (acceleration)
Freshman Physics 15 Force & Interaction
Day 2 Agenda: Pushy-Joe Simulation & Data Collection
Do Now:● What happens when
forces are balanced on an object?
● What happens when forces are unbalanced on an object?
Due TodayVectors Worksheet Due Next Class Pushy Joe
Freshman Physics 17 Force & Interaction
Pushy Joe Lab
Groups:A: GirlB: Bucket of WaterC: Girl holding the CrateD: Dude sitting on the Crate
Physics FP 18 Intro to Energy + Engineering a Wind Turbine
Pushy Joe Lab
Wild Guess: What is the acceleration of your object when FNet= 500 N?
Physics FP 19 Intro to Energy + Engineering a Wind Turbine
Pushy Joe Lab
Research Question:How does the Net Force acting on an object affect its acceleration?
Physics FP 20 Intro to Energy + Engineering a Wind Turbine
Pushy Joe Lab
Variables:1. Identify the independent variables.
2. Identify the dependent variables.
3. Identify the controlled variables.
Physics FP 21 Intro to Energy + Engineering a Wind Turbine
Pushy Joe LabHypothesis:
1) Sketch in graph form 2) In words “I think Net Force depends on
Acceleration in a ______ relationship”
Net
For
ce
Acceleration
Physics FP 22 Intro to Energy + Engineering a Wind Turbine
Pushy Joe Lab
Method:1. Procedure
2. How will you change the independent variables?
3. How will you control the controlled variables?
Freshman Physics 24 Force & Interaction
Pushy Joe Lab
● Use Desmos.com to graph your data and determine the equation of the best-fit line.○ Remember to use the Lincoln Start-up File
● Re-create your graph on the class-agreed scale
Freshman Physics 25 Force & Interaction
Pushy Joe Lab
● Write a 5-step Conclusion to the lab. ○ Remember to use your own equation and
your own mass for your data-informed prediction and confidence.
○ Use your Physics Binder as a resource/ reminder!
Freshman Physics 27 Force & Interaction
Measuring Forces Activity1. Complete the Prediction boxes for each
scenario.2. Show Mr. Hill complete boxes to get 2 spring
scales.3. Make measurements in Newtons (N).
Anchor Scenarios – need exemplar to stay up
Freshman Physics 28 Force & Interaction
If Time Allows: Mini-Lab
Prediction: How much 600 g will weigh?
Research Question: How is mass related to weight?
Freshman Physics 29 Force & Interaction
By the End of Class You Should…
Content Objective
Language Objective
Be able to identify balanced and unbalanced forces.
Be able to use words and arrows to describe forces.
Freshman Physics 31 Force & Interaction
Making Sense of Measuring Forces Activity
1. If an object doesn’t move what must be true about all the forces on the object?
2. In situation #5 you pulled 1 N and found the max force of friction to around 1 N, then in situation #6 you pulled 0.5 N, what can we infer about how hard friction resisted the motion in this case?
3. Big Idea: friction only pulls back as hard as you pull, up until it maxes out. Then it just pulls its maximum
Freshman Physics 32 Force & Interaction
Throwing Book on Table vs. Skateboard
Interaction-
If table pulls book (slowing it down); book must push on table.
Is this true?
Freshman Physics 33 Force & Interaction
Graphs Help Us See Patterns
Object Strength of InteractionSticky Book with lots of duct tape Very StrongSticky Book with little duct tape StrongSticky Residue from tape Pretty StrongSmooth Book MediumOn Pens Little
So let’s graph how objects moved based on the strength of their interaction with another object
Freshman Physics 34 Force & Interaction
Let’s get active!Super Strong Friction (a lot of tape)
High Friction (a little tape)
Medium Friction (a little masking tape)
Low Friction(just book)
Tiny Friction(book on pens)
Distance object rolls Force Needed to Keep It Moving
No Friction(imagine)
Freshman Physics 35 Force & Interaction
Title these graphs, regarding their Big Ideas
Super Strong Friction
High Friction
Medium Friction
Low Friction
Tiny Friction
Distance object rolls Force Needed to Keep It Moving
No Friction
Friction slows things down
It is natural to keep moving, friction is what makes thing stop
Freshman Physics 36 Force & Interaction
Super Sticky Friction
High Sticky Friction
Medium Friction
Low Friction
Tiny Friction
Force Needed to Keep Moving
Distance roll
Things in motion seem to stay in motion!
It is the force of friction that slows things down.
Freshman Physics 38 Force & Interaction
Key Vocabulary
Inertia: The property of all things to continue their motion until acted upon by a total force.
Freshman Physics 39 Force & Interaction
Making Sense of Measuring Forces Activity
1. If an object doesn’t move what must be true about all the forces on the object?
2. In situation #5 you pulled 1 N and found the max force of friction to around 1 N, then in situation #6 you pulled 0.5 N, what can we infer about how hard friction resisted the motion in this case?
3. Big Idea: friction only pulls back as hard as you pull, up until it maxes out. Then it just pulls its maximum
4. How can you achieve situation #10?
Freshman Physics 40 Force & Interaction
Key Vocabulary
Net Force: The total force on an object.
Equilibrium: all forces are balanced. Total force or Net Force is zero.
Freshman Physics 42 Force & Interaction
Day 3 Physics - Mr. Hill
Agenda: Finding Patterns in Force through Data Mining
Upcoming Events➢
Skywork Question:Scientist often utilize data that someone else already collected to answer their own new question
For example: Describe or Read “Mining Google searches for drug side effects”
Due Next Class Packet Page 5Due Today Rd 2.3 & 2.4, Q: 24-27: 14,15,23,26,27
Freshman Physics 44 Force & Interaction
By the End of Class You Should…
Content ObjectiveBe to evaluate a pre existing data set for its usefulness to
answer your question.
Language ObjectiveBe able to discuss a pattern with supporting evidence.
Freshman Physics 45 Force & Interaction
Experimenting on the Effect of Unbalanced Forces
Wild Guess: How far will the ball bearing roll from the ramp if the force of friction on the ball from the carpet is 0.031 N.
Research Question: Next slide, depends on what group you are in.
http://goo.gl/q8wqgP
Freshman Physics 46 Force & Interaction
Experimenting on the Effect of Unbalanced Forces
Group A how does the Applied Force change the motion of a ball?
Group B how does the Friction Force change the motion of a ball?
Group 1 How does an unbalanced total force affect acceleration?
Group 2 How does the mass affect acceleration?
Group C how does the speed change the effect of the total force on the motion?
Freshman Physics 47 Force & Interaction
Ramping Up our HypothesisHypothesis:
1) sketch in graph form (think about one set-up from
previous slide than think doubling or halving the width)2) in words “I think the ______ affects the
acceleration in a ______ relationship, this makes sense because ________”
acceleration
Your Parameter(Fa, Ff, Ftotal, mass, speed)
Freshman Physics 48 Force & Interaction
Experimenting on the Effect of Unbalanced Forces
Variables:1. identify the independent variables
2. identify the dependent variables
3. Identify the controlled variables
Freshman Physics 49 Force & Interaction
Find File at http://goo.gl/q8wqgP
Method:1. Open Data File and Orientate Yourself
• Scan headings• Total Force needs attention (equation, error, …)• What kind of carpet• What kind of balls are these
Freshman Physics 50 Force & Interaction
Experimenting on the Effect of Unbalanced Forces
Value of controlled variables:
SurfaceMass of
Ball (kg)
Force of Push on
Ball (N) +/-
0.2
Force of Friction on
Ball (N) +/- 0.2
Total Force on
Ball (N)
Starting Speed of the Ball
(MPH) +/- 0.3
Speed of the Ball after 10 Seconds (MPH) +/- 0.3
Change in Speed of the Ball over 10
Seconds (MPH/(10 s))
+/- 1
Change in Speed of the Ball over 1
Second(MPH/s) +/- 1
Carpet 0.4 2 0.05 1.95 1.0 1.0 0.0 0.0Carpet 0.5 2 0.05 1.95 0.0 1.0 1.0 0.1Carpet 0.6 2 0.05 1.95 3.0 6.0 3.0 0.3
Surface Mass of Ball (kg)
Force of Push on
Ball (N) +/-
0.2
Force of Friction on
Ball (N) +/- 0.2
Total Force on
Ball (N)
Starting Speed of the
Ball (MPH) +/-
0.3
Speed of the Ball after 10
Seconds (MPH) +/-
0.3
Change in Speed of the Ball over
10 Seconds (MPH/(10 s)) +/-
1
Change in Speed of the Ball over 1
Second(MPH/s) +/- 1
Carpet 0.5 0 0 0 10 10 0 0Carpet 0.5 0.1 0.05 0.05 11 12 1 0.1Carpet 0.5 0.2 0.05 0.15 14 17 3 0.3Carpet 0.5 0.3 0.05 0.25 0 5 5 0.5Carpet 0.5 0.4 0.05 0.35 7 14 7 0.7
Freshman Physics 54 Force & Interaction
Board MeetingMaking Sense of all this Data
1. Let’s orient ourselves to these graphs.2. Let’s start with acceleration vs mass.
1. What is the pattern?2. Why does this make sense?3. Where did the constant 4.9 come from?4. Why does this make sense?
3. What is going on in the acceleration vs total force graph?
Freshman Physics 58 Force & Interaction
Conclusion: Since the best-fit line of all our data is _____, I
conclude that there is a _______ relationship between the acceleration and ________. This can be represented mathematically:
So I predict through using computational reasoning that with a force of friction of ___ N, the ball will roll ___ m on the carpet. My confidence is _____ because _____________.
Next Slide
Freshman Physics 59 Force & Interaction
Computation Reasoning with Excel to get Prediction
Create a motion data table (t, x, v, a)Put in “a” from wild guess and pattern with force.Create dummy time intervalsSet and drag equations for v and xThen look for where ball stopsThen read x for that condition
Freshman Physics 60 Force & Interaction
Test Prediction
I get what Mr. Hill means when he says “we take some measurements about how much friction there is when you change the surface or how hard to press the surfaces together, apply some mathematics to find a pattern, and than we can predict the amount of friction there will be in a new case involving the same surfaces.
Freshman Physics 61 Force & Interaction
Prediction
Draw ramp, ball, and carpet and work from this drawing.
Freshman Physics 62 Force & Interaction
Test Prediction
Science works!We can find a pattern in nature and use it to
accurately predict the future.
Wild guess sometimes close, sometimes not. How do you know which of these it is? With careful investigation we can predict the future again and again – with some level of confidence.
Freshman Physics 63 Force & Interaction
Monday, January 7thPhysics - Mr. Hill
Agenda: Day 4Finish Experiment on Effect of ForcesReasoning about Force & InteractionsBalanced vs Unbalanced
Upcoming Next Friday➢
Skywork Question:1. What happens when forces are balance on an object?
2. What happens when forces on unbalanced on an object.
Due Next Class Packet Page 2 (except for Ff) & 6Due Today Packet Page 5
Freshman Physics 64 Force & Interaction
By the End of Class You Should…
Content ObjectiveHave a working understanding of the role of Inquiry & into
Science.
Language ObjectiveBe able to discuss a pattern with supporting evidence.
Freshman Physics 67 Force & Interaction
Forces
Ftotal = 0
Constant Velocity
Ftotal ≠ 0
Speeding up Slowing down
Balanced Unbalanced
Objects in motion tend to stay in motion.Objects at rest tend to stay at rest
When you really push,
things accelerate
Ftotal in direction of motion
Ftotal in opposite direction
as motionAt Rest Constant Motion
v = 0 v ≠ 0
? Acceleration ?
How do we complete this chart?
Freshman Physics 68 Force & Interaction
Put in ToolboxPhysics
1 – Inquiry & Patterns
2 – Motion & Energy
4 – Energy & Interactions
SI – Scientific Inquiry Fold Here
3 – Interaction & Forces
EP – Engineering Projects
Freshman Physics 69 Force & Interaction
Forces
Fnet = 0
Constant Velocity
Fnet ≠ 0
Constant Acceleration
Speeding up Slowing down
Balanced Unbalanced
Objects in motion tend to stay in motion.Objects at rest tend to stay at rest
When you really push,
things accelerate
Fnet in direction of motion
Fnet in opposite directionas motion
At Rest Constant Motion
v = 0 v ≠ 0
Freshman Physics 70 Force & Interaction
Key Vocabulary
Newton’s Second Law: Acceleration depends on both the total force and the mass of the object
Freshman Physics 71 Force & Interaction
Pattern: LinearAcceleration vs Net Force
When Force is doubled, acceleration is doubled
2
2
4
4
so when F F , a a
and when F F, a a
Freshman Physics 72 Force & Interaction
Pattern: InverseAcceleration vs Mass
When mass is doubled, acceleration will decrease by half4
42
2
so when m m, a a
and when m m, a a
Freshman Physics 74 Force & Interaction
Day 5 Physics - Mr. Hill
Agenda:Reasoning about ForcesUsing Force Analysis to solve problemsSQPRRS
Upcoming Next Week ➢ Short Answer Quiz on Forces
Skywork Question:Can there be an interaction with a single object?
Due Today Packet Page 2 (except for Ff) & 6Due Next Class Rd 6.1-6.3 Q’s: 1,2,5,6,21,22,23,31,33
Freshman Physics 75 Force & Interaction
By the End of Class You Should…
Content ObjectiveYou should be able to distinguish between forces within an
interaction and multiple forces on a single object.
Language ObjectiveBe able to use accurately use ‘force pairs’ and ‘total force’
to describe physical scenarios.
Freshman Physics 83 Force & Interaction
A B
Person A pulls on metal
Metal pulls on _____
Person B pulls on metal
Metal pulls on _____
Freshman Physics 84 Force & Interaction
A BPerson A pushes metal
Metal pushes ______
Person B pushes metal
Metal pushes _____
Freshman Physics 86 Force & Interaction
Reasoning about Force & Interactions
Explaining through cartoons these three scenarios with a cyclist:1. Cyclist pedals kind of strong to go a constant 10
mph.2. Cyclist pedals super strong to speed up to 25 mph.3. Cyclist then has to pedal medium strong just to
stay going a constant 25 mph.
Visually: scene, Fpedal, Fair resistance, Fnet, Balance/Unbalanced
+ 1 sentence reasoning
Anchor Scenarios - need on poster paper to stay up
Freshman Physics 87 Force & Interaction
Analyzing Surprising Situations with ForcesErin says “Mr. Hill that stuff about interaction can’t be
right. When I drop a basketball it falls to the earth, the earth doesn’t also fall towards the basketball.”
Think. Pair. Share. Write.
Mass of Basketball 0.6 kgMass of Earth 6000000000000000000000000 kg
Force of interaction on each other W = mg = 6 NWhat impact will that have in changing each of their motions?
What sort of acceleration is involve for each? What about of time is the change happening for? What will be the net movement of each in this time?
Need on poster paper to stay up
Freshman Physics 88 Force & Interaction
SQPRRS 6.1-6.3On Whiteboards
SurveyQuestionPredictReadRespondSummarize
Due Tomorrow Rd 6.1-6.3 Q’s: 1,2,5,6,21,22,23,31,33
Freshman Physics 89 Force & Interaction
Check In: You Should…
Content ObjectiveYou should be able to distinguish between forces within an
interaction and multiple forces on a single object.
Language ObjectiveBe able to use accurately use ‘force pairs’ and ‘total force’
to describe physical scenarios.
Freshman Physics 90 Force & Interaction
Day 6 Physics - Mr. Hill
Agenda: Cover HomeworkUsing Force Analysis to solve problemsExperimenting with Friction
Upcoming Next Week ➢ Short Answer Quiz on ForcesDue Next Class Packet Page 7 Due Today Rd 6.1-6.3 Q’s: 1,2,5,6,21,22,23,31,33
Skywork Question:How could we make the frictional force between a book and the table bigger?
Freshman Physics 91 Force & Interaction
By the End of Class You Should…
Content ObjectiveHave a working understanding of patterns with friction
Language ObjectiveBe able to discuss the patterns friction using supporting
evidence.
Freshman Physics 93 Force & Interaction
In an experiment, you use a spring scale to pull a 0.5 kg wood block. You observe the block does not move at first, even when you pull with 2.0 N of force. Immediately after pulling the slightest bit harder the block begins to accelerate.
Freshman Physics 95 Force & Interaction
Connecting to These Scenarios
Make your cartoons quantitative for the three scenarios with a cyclist:1. Cyclist pedals kind of strong to go a constant 10
mph.2. Cyclist pedals super strong to speed up to 25 mph.3. Cyclist then has to pedal medium strong just to
stay going a constant 25 mph.
Visually: scene, Fpedal, Fair resistance, Fnet, Balance/Unbalanced
+ 1 sentence reasoning
Need on poster paper to stay up
Freshman Physics 96 Force & Interaction
Experimenting with the Force of Friction
Wild Guess: How hard will you have to pull 6 Physics Text Books to keep them moving if they are stacked on top of 10 round pens that are on the table?
Research Question: How do surfaces and amount of force the
surfaces are pressed together affect friction?
Freshman Physics 97 Force & Interaction
Experimenting with the Force of Friction
Group A: How does the strength of friction for a book on table top depend on how hard the book and tabletop are pressed together?
Group B: How does the strength friction for a book on pens depend on how hard the book and pens are pressed together?
Group C: How does the strength of friction to start a book on table top moving depend on how hard the book and tabletop are pressed together?
Freshman Physics 98 Force & Interaction
Experimenting with the Force of FrictionHypothesis:
1) Sketch in graph form (think about one set-up from
previous slide than think doubling or halving the width)2) In words “I think the force pressed together
affects the force of friction in a ______ relationship”
Force of FrictionFf
Force pressed together(weight)
2 lines: 1 for book on table 1 for book on pens 1 for book stuck on table
Freshman Physics 99 Force & Interaction
Experimenting with the Force of Friction
Variables:1. Identify the independent variables
2. Identify the dependent variables
3. Identify the controlled variables
Freshman Physics 100 Force & Interaction
Experimenting with the Force of Friction
Method:1. Experimental set-up
2. How will you change the independent variables?
3. How will you control the controlled variables?
Freshman Physics 101 Force & Interaction
Experimenting with the Force of Friction Value of controlled variables: g = 10 m/s2 ; book = ___ N
Force PressedTogether
(N) +/- __
Force of Friction (N) +/- ___ Average Friction
(N)Uncertainty in Friction
(N)
Trial 1 Trial 2 Trial 3
0
17
34
51
if books stays at constant velocity
Freshman Physics 102 Force & Interaction
Experimenting with the Force of Friction
What is this?
25 50
10
25
Force Pressed Together (N)
Fric
tion
(N)
5
20
15
Freshman Physics 104 Force & Interaction
Day 7 Physics - Mr. Hill
Agenda: Making Sense of the Patterns
with FrictionReading about Free Fall and Air Resistance
Upcoming Next Week ➢ Short Answer Quiz on Forces
Skywork Question:
Due Today Packet Page 7 & complete all of 2 Due Next Class Rd 6.6 & 6.7 Q’s: 13,15,17,19,38,47
Freshman Physics 105 Force & Interaction
By the End of Class You Should…
Content ObjectiveHave a working understanding of the role of Inquiry & into
Science.
Language ObjectiveBe able to discuss a pattern with supporting evidence.
Freshman Physics 107 Force & Interaction
Experimenting with the Force of Friction
What is this?
25 50
10
25
Force Pressed Together (N)
Fric
tion
(N)
5
20
15 friction = ____ * force pressed together
friction = ____ * force pressed togetherstatic
rolling
Freshman Physics 109 Force & Interaction
Experimenting with the Force of Friction
stickiness factor
stickiness factor
Freshman Physics 110 Force & Interaction
Experimenting with the Force of FrictionConclusion: Since the best-fit line of our data is linear for both
static and rolling situations, we conclude that there is a linear relationship between the force of friction and the force two objects are pressed together. This can be represented mathematically
So I predict with ______ confidence, it will take __ N to pull a pile of 6 books stack on 10 rounds pens on a table, because __________.
static friction = ____ * force pressed togetherrolling friction = ____ * force pressed together
Freshman Physics 111 Force & Interaction
Application QuestionExplain by referencing data, why we often put
things on wheels or ball bearings when we want to easily or efficiently move things.
As can be see in the graph of friction vs normal force, the ________ can be reduced by a factor of _____ by using wheels. That is, for a box weighing 20 N the friction without wheels would be _____ N and be reduce to only _____ N with wheels.
Freshman Physics 112 Force & Interaction
Test Prediction
I get what Mr. Hill means when he says “we take some measurements about how much friction there is when you change the surface or how hard to press the surfaces together, apply some mathematics to find a pattern, and than we can predict the amount of friction there will be in a new case involving the same surfaces”.
Freshman Physics 113 Force & Interaction
Test Prediction
Science works!We can find a pattern in nature and use it to
accurately predict the future.
Wild guess sometimes close, sometimes not. How do you know which of these it is? With careful investigation we can predict the future again and again – with some level of confidence.
Freshman Physics 114 Force & Interaction
SQPRRS 6.6 & 6.7
SurveyQuestionPredictReadRespondSummarize
Due Tomorrow Rd 6.6 & 6.7 Q’s: 13,15,17,19,38,47
Freshman Physics 115 Force & Interaction
Day 8 Physics - Mr. Hill
Agenda: Short Answer QuizFree Fall, Air Resistance,
& Terminal VelocitySeeing Forces in Motion Graphs
Skywork Question:
Due Next Class Packet Page 8Due Today Rd 6.6 & 6.7 Q’s: 13,15,17,19,38,47
Freshman Physics 116 Force & Interaction
By the End of Class You Should…
Content ObjectiveHave a working understanding of the role of Inquiry & into
Science.
Language ObjectiveBe able to discuss a pattern with supporting evidence.
Freshman Physics 118 Force & Interaction
New Idea: Free Fall
Physics Physics
Physics
When a book, two books, and a crumpled sheet of paper are dropped at the same time rank the order in which they will hit the floor?
Why?
Freshman Physics 119 Force & Interaction
New Idea: Free Fall
Physics Physics
Physics
Video: What happens when remove the air?
Why?
Freshman Physics 120 Force & Interaction
Key Vocabulary
Free Fall: Falling without significant air resistance.
Terminal Velocity: The max speed an object can fall; since air resistance balances out the force of gravity causing the object to no longer speed up and instead it falls at a constant speed.
Freshman Physics 121 Force & Interaction
New Idea: Free Fall
Physics Physics
Physics
At terminal velocity: let’s draw the forces on each object, label our guess at the time of fall it reaches terminal, and the speed it has when it does reach terminal velocity.
Why?
Freshman Physics 122 Force & Interaction
Review Data Tables Involving Acceleration
TimeAcceleration
(m/s2)Velocity
(m/s)Distance
(m)
0
1
2
3
4
5
Skydiving
Freshman Physics 123 Force & Interaction
The next slide involves skydiving with air resistance in a qualitative fashion. It should noted that it will
look similar to constant acceleration at first then transition to looking like constant velocity when it reaches its terminal velocity. We will use this to
introduce on forces show up in motion graphs.
Freshman Physics 124 Force & Interaction
Data Tables Involving Acceleration
TimeAcceleration
(m/s2)Velocity
(m/s)Distance
(m)
0
1
2
3
4
5
Skydiving with Air Resistance
Freshman Physics 128 Force & Interaction
Day 9 Physics - Mr. Hill
Agenda: Practice with Science Literacy
Skywork Question:
Sample Passage next Slide
Due Today Packet Page 8Due Next Class Practice Science Literacy Reading
Freshman Physics 129 Force & Interaction
By the End of Class You Should…
Content ObjectiveBecome familiar with one framework of complex text.
Language ObjectiveDevelop two new strategies for reading non-fiction texts.
Freshman Physics 133 Force & Interaction
Dive In: Try Stopping Distance
5 minutes, then I will model my strategies.
Freshman Physics 134 Force & Interaction
Teacher Model with ACT Question
As I carefully read this passage, I will talk out loud the ideas and strategies I use.
Freshman Physics 135 Force & Interaction
Teacher Guides ACT Question
You work through a passage a notice what strategies you use and where you get stuck. First attempt to see if any strategy we discussed will help if not then ask me.
Freshman Physics 136 Force & Interaction
Teacher Steps-Aside ACT Question
No short-cuts you must practice to get better – but be intentional about your practice or it is wasted.
Of course, I will help you but you are really seeing what you are capable of here.
Freshman Physics 137 Force & Interaction
Day 10Physics - Mr. Hill
Agenda:Applying Forces
to a BridgeReview Force Unit
Due Today Science Literacy QuestionDue Next Class Review Sheet
Skywork Question:Think of an object that would fit for each of the following 3 scenarios:You lightly push and it doesn’t move.You lightly push and it barely moves at a constant speed.You lightly push and it quickly accelerates away.
Freshman Physics 138 Force & Interaction
By the End of Class You Should…
Content ObjectiveHave a working understanding of the role of Inquiry & into
Science.
Language ObjectiveBe able to discuss a pattern with supporting evidence.
Freshman Physics 139 Force & Interaction
Finding Fnet and the resulting Acceleration
3 N
4 N
Mass is 2 kg
Freshman Physics 141 Force & Interaction
Finding Fnet and the resulting Acceleration
A 3D example
Push: 3 N to the right
Push: 4 N BackwardsMass of block = 0.1 kg
Support Force: 1 N upWeight: 1 N Down
Freshman Physics 142 Force & Interaction
Force Situation that will come up in bridge project
Wall Wall
Beam ( 20 kg)
10 kg
Wall Wall
Beam ( 20 kg)
Wall Wall
Beam ( 20 kg)
10 kg
Wall Wall
Beam ( 20 kg)
10 kg
Freshman Physics 146 Force & Interaction
Force Situation that will come up in bridge project
Ground, Right
Ground, left
50N
ca b
d
Freshman Physics 147 Force & Interaction
Ground, Right
Ground, left
50N
ca b
d
1. Identify the forces acting inside beams A through D
2. Assuming that each beam has negligible mass (meaning that you do not have to think about it when calculating the weight) find the Weight that is being supported by the two support walls.
Freshman Physics 149 Force & Interaction
Pattern: LinearAcceleration vs Net Force
When Force is doubled, acceleration is doubled
2
2
4
4
so when F F , a a
and when F F, a a
Freshman Physics 150 Force & Interaction
Pattern: InverseAcceleration vs Mass
When mass is doubled, acceleration will decrease by half4
42
2
so when m m, a a
and when m m, a a
Freshman Physics 151 Force & Interaction
In an experiment, you use a spring scale to pull a 0.5 kg wood block. You observe the block does not move at first, even when you pull with 2.0 N of force. Immediately after pulling the slightest bit harder the block begins to accelerate.
Freshman Physics 153 Force & Interaction
Revisiting These Scenarios
Make your cartoons quantitative for the three scenarios with a cyclist:1. Cyclist pedals kind of strong to go a constant 10
mph.2. Cyclist pedals super strong to speed up to 25 mph.3. Cyclist then has to pedal medium strong just to
stay going a constant 25 mph.
Visually: scene, Fpedal, Fair resistance, Fnet, Balance/Unbalanced
+ 1 sentence reasoning
Need on poster paper to stay up
Freshman Physics 154 Force & Interaction
Analyzing Surprising Situations with ForcesErin says “Mr. Hill that stuff about interaction can’t be
right. When I drop a basketball it falls to the earth, the earth doesn’t also fall towards the basketball.”
Think. Pair. Share. Write.
Mass of Basketball 0.6 kgMass of Earth 6000000000000000000000000 kg
Force of interaction on each other W = mg = 6 NWhat impact will that have in changing each of their motions?
What sort of acceleration is involve for each? What about of time is the change happening for? What will be the net movement of each in this time?
Need on poster paper to stay up
Freshman Physics 159 Force & Interaction
Day 11Physics - Mr. Hill
Agenda: Air Resistance Experiment
Upcoming This Friday➢ Test on Energy & Forces
Skywork Question:If there is no air resistance all objects accelerate at 10 m/s2, but what happens if there is air resistance?
Sketch a graph of Fnet vs time for a book and a coffee filter are dropped off the stadium 15 m high.
Due Today Packet 8,2,7Due Tomorrow Packet 13
Freshman Physics 160 Force & Interaction
By the End of Class You Should…
Content ObjectiveHave a working understanding of the role of Inquiry & into
Science.
Language ObjectiveBe able to discuss a pattern with supporting evidence.
Freshman Physics 161 Force & Interaction
Experimenting with Air Resistance
Wild Guess: How long will it take a coffee filter and a book to fall 4.5 meters?
(Observation – )
Research Question: How air resistance affects Fnet and velocity of
objects?
Freshman Physics 162 Force & Interaction
Experimenting with Air ResistanceHypothesis:
1) Sketch in graph form (think about one set-up from
previous slide then think doubling or halving the width)
v
t
• book
◆ coffee filter
Freshman Physics 163 Force & Interaction
Experimenting with Air Resistance
Variables:1. Identify the independent variables
2. Identify the dependent variables
3. Identify the controlled variables
Freshman Physics 164 Force & Interaction
Experimenting with Air Resistance
Method:1. Experimental set-up
2. How will you change the independent variables?
3. How will you control the controlled variables?
Freshman Physics 165 Force & Interaction
Experimenting with Air Resistance Value of controlled variables: Book = kg Filter = kg
ObjectHeight Fell(m) +/- 0.02
Max Velocity (m/s) +/- 0.2 Average Max Velocity
(m/s) +/- 0.2Trial 1 Trial 2 Trial 3
Filter
Book