€¦ · Web viewMathematical Language Word problems describe science or math problems in words. To solve a word problem, you need to translate the language of words to the language

Additional Resources (U1L1) Levers ModuleReading StrategiesThese reading tools will help students learn the material in this unit: Science Terms, Describing Space and Time, and Foldable.

Science Terms, Many words used in science are familiar words from everyday speech. However, when these words are used in science, their meanings are often different from or are more precise than the everyday meanings. As students pay attention to the definitions of these words their correct use of them in scientific contexts will improve. Have students set up a table in their scientific/engineering notebooks with three columns as seen below. As students are introduced to vocabulary, have them complete the table for the new term.

Mathematical Language Word problems describe science or math problems in words. To solve a word problem, you need to translate the language of words to the language of equations, mathematical symbols, variables, and numbers. Students would complete a table like the one below for the following word problem. A crane uses an average force of 5,200 N to lift a girder 25 m. How much work does the crane do on the girder?

Concept Maps, A concept map is a diagram that helps you see relationships between the key ideas and categories of a topic. To construct a concept map, do the following: Select a main concept for the map. List all of the other related concepts. Build the map by arranging the concepts according to their importance under the main concept. Add linking words to give meaning to the arrangement of concepts.

Bell Ringers/Warm-up Exercises1. Mark Up The Text (MUTT) – What is a horsepower? Have students answer the following questions

on their Journal or Daily Lesson Log once they have completed MUTTing the article: What did you learn from the article? What is one fact that surprised you from the article? What is one question you have after reading the article?

2. Mark Up The Text (MUTT) – It’s A Balancing Act: Levers, Have students MUTT the Build it Yourself and Construction Procedure sections of the Lever Investigation in preparation of making their

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testing apparatus. Have students answer the following questions on their Journal or Daily Lesson Log once they have completed MUTTing the article: What are you going to build? What tools will you need to build your device? How does your device work?

3. Levers Background Information Quiz, Establish 4-5 questions that will gauge whether students have read, and understand, the material in the background section of the Lever Investigation activity. This can be handed out as students enter the classroom or in a more formal manner after class has begun. You may choose to use the following: What is required to make an object move? What are the three requirements for work to take place? What is mechanical advantage? What is the formula for calculating work? What is the equation for equilibrium and what does it tell us about a given situation?

4. ABC Chart, Vocabulary/Reading Strategy, Have students complete the ABC Chart for the terms; Vectors, Newton’s Laws, Mechanical Advantage. This graphic organizer will help students brainstorm all they know about the term. Students complete the chart by writing a term or short phrase that starts with each letter of the alphabet. Once students have completed the chart as their warmup activity, go around the room and have students provide the term they used for a specific letter in the alphabet. Try to complete an ABC Chart from classroom participation.

5. Word Web, Vocabulary/Reading Strategy – Levers, Have students create a Word Web for the term Levers. Students should include all the information they can recall from the past lessons to create connections between concepts, equations, and experimental data.

PowerPoint Slide Show PresentationsThe following presentation resources are available on the Hardware Stores Science website.

PowerPoint Slide Show Presentation, Work, This slideshow covers the fundamentals of Work. It is geared towards the simplest forms of work, where the direction of force is perpendicular or parallel to the motion of the object. This way students are able to learn the concept of work without the added confusion of vectors and the use of complex math. Explain to students that work is a combination of force, displacement and cause. Ensure students understand that these three conditions must be met in order for work to take place. Explain that work can be done against another force (i.e. gravity) or to change motion (i.e. speed). Ensure students understand the difference between work input and work output as well as the input force and the output force.

PowerPoint Slide Show Presentation, Levers and Equilibrium, Use this slide show to review with students the concept of levers and mechanical advantage. Pay particular attention to the forces involved in a lever and student understanding of those forces. Ensure students have a thorough understanding of the role the distance of the force from the fulcrum plays in determining the work input and output. When discussing how to calculate work and mechanical advantage, ensure students understand how to properly manipulate mathematical equations.

Printable ResourcesThe following resources are found in the Appendix and are available on the Hardware Stores Science website.

Daily Lesson LogABC Chart

Online ResourcesThe following resources are found online, and can be accessed through their individual websites or in a word document version at the Hardware Store Science website. One advantage of using the word


document version of this article is that educators are able to download and edit the document with questions, writing prompts or other student suggestions.

What is Horsepower? – This article was written by Sara Chodosh, May 10, 2018. It can be found the Popular Science website at https://www.popsci.com/what-is-horsepower or a word document of this article, without the ads and other distractors, can be found at hardwarestorescience.org

Background Information: Speed Velocity and AccelerationWhen dealing with speed, students should be familiar with concepts like miles per hour and meters per second. At the grade level this material is addressed, students should be able to calculate a speed using the formula

speed=distancetime

=dt

It is important to remember that these values are generally average speeds; the speed at any instance, instantaneous speed, may be different.

Velocity may be a new concept for students, and understanding that velocity is made up of both the speed and direction of an object may be a bit of a challenge for a few. Add to this the idea that a quantity that specifies direction as well as magnitude is called a vector quantity and students will now begin to struggle with the math connected to this fundamental physical science content.

A second difference between speed and velocity is that the average velocity is defined in terms of displacement, rather than the total distance traveled.

vavg=displacementelapsed time

= final position−initial positionelapsed time

=x final−x initial

t2−t 1=∆ x

∆ t

Velocity, like speed, by its very nature is always a positive number due to the simple fact that you cannot conceptually have negative velocity. Mathematically, on the other hand, if xfinal is less than xinitial the resulting value will be a negative number. Whether velocity is a (+) or (-) value indicates that the object in motion is moving to the right (east) or left (west) respectively. The direction of velocity is always the same as the displacement.

When an object’s velocity is changing it is said to be accelerating, and the average acceleration can be determined much that same way as the average velocity.

aavg=change∈velocity

elapsed time= final velocity−initial velocity

elapsed time=

v final−v initial

t 2−t 1=∆ v

∆ t

Acceleration, by default is a vector quantity due to the fact that it contains a velocity which is itself is a vector quantity. A second note on acceleration is that acceleration can be either positive (+) or negative (-) depending upon the values for the final and initial velocities. The (+) or (-) value of acceleration indicates whether an object is speeding up (positive acceleration) or slowing down (negative acceleration). This will be a bit confusing for students who are conditioned to acceleration always being referred to objects that are speeding up and deceleration describing objects that are slowing down.


When placed on a coordinate axis (+) acceleration would be to the right and (-) acceleration would be to the left. This can be challenging for most students to truly grasp and understand.

Another mental hurdle for students to face will take place as you discuss that when any object moves, this motion will be relative to something else. It will be helpful to assist students in understanding that unless stated otherwise, all speeds, velocities and accelerations will be relative to an observer on the surface of the earth. It may be helpful for them to place themselves as the reference point an then all motion would be to their right, left, up and down.

The study of motion, and the related concepts of force and energy are essentially the study of mechanics and are normally divided into two subcategories: kinematics, which is the description of how objects move, and dynamics, which deals with force and why objects move as they do. It is easier for students to grasp the new and challenging content of physical science if they first focus on non-rotating objects. This non-rotating motion is called translational motion, or the motion of an object along a straight-line path. Once this is mastered then they will be ready to move onto motion in two (or three) dimensions along paths that are not straight.

A third mental hurdle students will face will be; any measurement of position, distance, or speed requires some frame of reference to accurately describe it. This can be effectively dealt with by adopting a frame of reference using north or “up”, south or “down”, east or “right”, and west or “left”. This will allow students to draw a set of coordinate axes. By convention, when dealing with situations involving one dimensional motion, the horizontal line along which the motion takes place is designated as the x axis. If the motion is vertical, the y axis is used.

Vectors and Vector Quantities

Because velocity contains a magnitude and a direction, both must be considered at the same time. Any time a magnitude and a direction must be included the resulting answer will be a vector quantity. Vector quantities include displacement, force and momentum. Unlike values that have no direction to them (scalar quantities), vector quantities must be dealt with using specific types of mathematics.

To assist students in understanding, and learning, this “new” math it may be helpful to have them draw simple diagrams when dealing with vectors. Students will represent vector values with an arrow and its associated value.

Arrows will always be drawn so that they point in the direction that the accompanying value represents and the length of the arrow is normally proportional to the value as well, though this is less critical.

Many textbooks and articles will write the symbol for a vector using boldface type, with a tiny arrow over the symbol. Velocity would be written v⃗. If only the magnitude of the vector is required they will simply write v, in italics.

Adding vector quantities must be done in a special way because there are both direction and magnitude components. If vectors are in the same direction, or


along the same coordinate line, simple addition and subtraction can be used. This is made possible by the adoption of a coordinate axis frame of reference using north or “up”, south or “down”, east or “right”, and west or “left”.

The result of a vector equation is referred to as the net or resultant displacement. A simplified version of adding vectors together would look something like the following.

5¿+5¿=10¿ 5¿−5¿0

10up−5 down=5up

5+10=15 5−10=−5

This simplified version of vector addition and subtraction cannot always be used. Often the motion of an object is not straight forward, up, down, or backwards. Many times motion is at an angle; northeast, southwest, west by northwest. In the cases when vectors are in directions that are not in the same direction or along different coordinate lines then a more complicated mathematical process must be employed.

The magnitude or length of the resulting displacement can be determined using the Pythagorean Theory.

Combined with some fundamental trigonometry in the form of

SOH CAH TOA

Let’s first look at a diagram that has used a tail-to-tip method of displaying vectors.

Purdue Pete leaves the football stadium and walked 9 km east and then 5km north. Determine Pete’s resulting displacement.

This problem asks us to determine the result of adding two displacement vectors that are at right angles to each other. The net (or resultant) displacement of walking 9 km east and 5 km north is a vector directed both east and north as shown in the diagram below. Since the eastward displacement and the northward displacement are at right angles to each other, the Pythagorean theorem can be used to determine the resulting displacement (i.e., the hypotenuse of the right triangle).


a2+b2=c2

c2=a2+b2

c=√a2+b2=√92+52=10.3units

The direction of a resultant displacement can often be determined by using the trigonometric mnemonic SOH CAH TOA. This relates the acute angle of a right triangle, or in other words the angle of displacement in relation to the coordinate axis, to the lengths of two of the sides of the right triangle. SOH relates the angle to the ratio of the side opposite the angle to the hypotenuse.

sin θ= oppositehypotenuse or sin θ=b

c

CAH relates the angle to the ratio of the side adjacent the angle to the hypotenuse.

cosθ= adjacenthypotenuse or cosθ=a

c

TOA relates the angle to the ratio of the side opposite the angle to the side adjacent to the angle.

tanθ= oppositeadjacent or tanθ=b

a

These three trigonometric functions can be applied to Purdue Pete in order to determine the direction of his overall displacement. We must first select one of the angles other than the right angle of the triangle; let’s choose the angle associated with the horizontal (x) displacement. We can then use the equation that relates the side opposite the angle with the side adjacent to the angle.

tanθ= oppositeadjacent

Rearranging this equation and solving for θ gives

θ=tan−1 oppadj

=tan−1 59=29.1o


Once the angle is selected however, any of the three functions can be used to find the measure of the angle.

θ=sin−1 510.3

=29.1o

θ=cos−1 910.3

=29.1o

Granted this whole process could have been done using a ruler and a protractor. The strength of this method lies in the fact that all motion can be reduced down to a set of x and y components of a coordinate axis.

Resolving Vector ComponentsAs mentioned earlier, a vector can be directed at angles to the customary coordinate axes. In these situations the vector can be transform into two parts. For example, a vector that is directed northwest can be thought of as having a northward part (component) and a westward part (component).

Any vector can be thought of as having these two parts and each part is known as a component of the vector. The combined influence of the two components is equal to the overall vector. Thus, any vector could be replaced by its two components.

Imagine you are walking your dog with a leash stretched upward and back as it is upped tight. The tension within the leash has two components - an upward component and a leftward component. The influence of the leash on your dog’s is equivalent to the influence of two individual leashes acting on his body - one pulling upward and the other pulling rightward.

All vectors that are at an angle to the horizon (or are vertical) can be thought of in relation to these two parts or components. With patience and encouragement students are capable of learning how to resolve vectors into two components and then determining the magnitudes of the components of a vector directed in two dimensions.

The trigonometric method of vector resolution discussed previously can be used to determine the components of a single vector. Trigonometric functions relate the ratio of the lengths of the sides of a right triangle to the measure of an acute angle within the right triangle. Therefore, these same functions can be used to determine the length of the sides of a right triangle if an angle measure and the length of one side are known.


This can easily be accomplished by first creating a rough sketch of the vector in the indicated direction. Label its magnitude and the indicated angle that it makes with the referenced point.

Draw a horizontal arrow beginning at the origin of the vector. Then draw a vertical line from the head of the vector, down until the two lines will meet to form a rectangle.

The vector components are now the sides of the triangle just drawn. Place arrowheads on these components to indicate their direction (up, down, left, right). Having students label each component of the vectors will help them indicate which component represents which side. The northward velocity component might be labeled vy. The rightward velocity component might be labeled vx.

Students will now be able to determine the length of the side opposite the indicated angle using the sine function. Have them substitute the magnitude of the vector for the length of the hypotenuse and the degree of angle for the theta (θ) symbol. Students then rearrange the equation and solve for the unknown value.

sin θ=opphyp


hyp × sin θ=opp

50m /s× sin 60=43.3m /s

Repeat the above step using the cosine function to determine the length of the side adjacent to the indicated angle.

hyp× cosθ=adj

50×cos 60=25m /s

Summary: A vector directed in two dimensions has two components - that is, a component in two separate directions. The value for each component can be determined using the trigonometric method of vector resolution.

Many problem scenarios in a typical physics course will involve the addition of three or more vectors. Though this course will not involve these complicated scenarios, teaching students this method now will prepare them for future opportunities within those courses and give them practice with these skills in simplified situations.

Motion and the force that causes itSome sort of force is required to make an object move and when a force causes the movement of an object it is said that work was done upon the object. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause a displacement. There are several good examples of work that can be observed in everyday life - a horse pulling a plow through the field, a father pushing a grocery cart down the aisle of a grocery store, a student lifting a backpack full of books upon her shoulder, a weightlifter lifting a barbell above his head, an Olympic athlete launching the shot-put, etc. In each case there is a force exerted upon some object to cause that object to be displaced (moved).

In it’s simplest form we can calculate the amount of work done by multiplying the force applied to an object by the distance in which the object moves.

W =Fxd where F is the force, d is the displacement

Using the equation above would tell us that 30 N·m of work was done when a force of 10 Newtons (N) is applied to an object and moves that object 3 meters.

10N x 3m=30N ∙ m

Interestingly enough, energy is also measured in units of N·m with one Joule being equal to 1 Newton of force exerted over a distance of 1 meter. The property of an object, or system, that enables it to do work is Energy. Like work, energy is measured in units of Joules. So, another way of saying this is that 30 Joules of work were done on the object.

Imagine that you are holding a brick above the ground. Your arm is straight out in front of you and it's pretty tough to hold. Slowly, your arm gets tired, the brick feels heavier and heavier. Even though you put forth a lot of effort to hold the brick up, if the brick doesn't move no work is being done. If you lifted the brick again after your arm had rested, that would be work. A force is required to maintain the position of the brick but, by definition, without a displacement there was no work done.


Because work and energy are equivalent units, we are able to say that work transfers energy from one object to another. Energy appears in many forms that will be discussed in future experiments. The energy due to the position of something or an objects movement is termed mechanical energy.

Simple Machines and Mechanical AdvantageSimple machines are devices that transfers the applied, or input, into an output force. This is often accomplished by changing the distance through which we apply the force. The word for “machine” comes from the Greek word meaning “to help make things easier.” Levers, gears, and pulleys are well known examples of simple machines. These devices change the amount of effort required to move an object by reducing the input force that is needed to perform the job. The ratio of output to input force magnitudes for any simple machine is called its mechanical advantage (MA).

MA=Foutput

F input

A lever is a rigid object that pivots at a fixed place called the fulcrum. Distances from the physical pivot of the lever are crucial, and we can obtain a useful expression for the mechanical advantage in terms of these distances.

A pry bar is a lever with a large mechanical advantage. The force that is applied at one end of the pry bar is transferred to the other end of the pry bar. Notice that the force being applied is causing one end of the pry bar to move downward while the other end move upward. Because there is displacement, and that displacement is caused by a force, work has been done. Notice also that the amount of work done on one end of the pry bar is equal to the amount of work done on the other end of the pry bar.

W =Fxd=80Nx 18

m=10N ∙m W =Fxd=10Nx1m=10N ∙m

What interests us most here is that the magnitude of the force exerted by the pry bar is much greater than the magnitude of the input force applied to the pry bar at the other end.

Taking a closer look at the diagram above provides a couple of clues about why the work done on both sides of the fulcrum are equal. First the distance between the fulcrum and the input force is large compared to the distance between the fulcrum and the output force. Second, the amount of effort required to move the mass is less.


This can be represented mathematically as indicated by the equation below.

F input A=Foutput B

where A and B are the distances from where the input and output forces are applied to the pivot. Rearranging the last equation gives

Foutput

F input= A

B

Thus, mechanical advantage can be restated as

MA=Foutput

F input= A

B

This equation is true for levers in general. For the pry bar, the MA is certainly greater than one. The longer the handle on the pry bar, the greater the force you can exert with it. The images below show the three common ways of arranging the input force, output force, and fulcrum to create Three different types of levers. All these lever types are similar in that there is an input force, the output force, and the fulcrum or the pivot – each one with its own mechanical advantage.


For a type 1 lever, you push down on one end and lift a load at the other. The directions of input and output are opposite.

For a type 2 lever, you lift the end of the lever. Since the input and output forces are on the same side of the fulcrum, the forces have the same direction.

For a type 3 lever, the input force is applied between the fulcrum and the load. The input and output forces are on the same side of the fulcrum and have the same direction.

EquilibriumA lever is a simple machine made up of a beam or solid rod and a fulcrum or pivot point. The beam is placed so that some part of it rests on top of the fulcrum. In a traditional lever, the fulcrum remains in a stationary position, while a input force is applied somewhere along the length of the beam. The beam then pivots around the fulcrum, exerting the output force on some sort of object that needs to be moved.

The key concepts at work in the lever is that the work done into one end of the lever (labeled effort) will manifest as an equivalent amount of work on the other end (labeled load).

If the distances from the fulcrum are the same (A = B) then the lever is going to balance out provided that the weights are the same (m1 = m2). If known weights on one end of the fulcrum have been used then the weight on the other end of the fulcrum can easily be determined to balance the other end.

The situation gets much more interesting when m1 does not equal m2. In these situations the mathematical relationship between the product of the mass and the distance on both sides of the lever can be utilized to determine relative distances from the fulcrum.

m1 A=m2B


LoadEffort

m2

BAm1

This would also hold true if distances were known and mass was wanted. While the assumption discussed above is that there are objects of a given mass sitting on the beam, the object could be replaced by anything that exerts a physical force upon the lever.

Hardware Store Science and MakingTo effectively teach science, teachers need resources — and usually a lot of resources like; specialized equipment, tools, and supplies not to mention resources for projects, models, and demonstrations. These things don’t come cheap. That means teachers often have to spend a significant amount of time altering lesson plans to accommodate resources. The era of open-source software and cheap hardware, including 3-D printers, is making it easier for teachers to provide the resources students need to do some forms of scientific investigations. Still the costs of these technologies typically limit their inclusion to the dominion of more affluent schools. As a result many teachers have begun to embrace the build-it-yourself mentality to provide their students with a variety of learning opportunities for such topics as energy, motion, and forces. These “maker” skills and mentality have to potential of transforming the science classroom into a unique learning environment.

In the hands of students, maker skills and tools can help transform abstract concepts into tangible objects, especially those students and classrooms who need a piece of equipment that doesn’t exist or is too expensive to purchase using available funds.

Maker Pedagogy has been defined as “an approach that utilizes the principles of ethical hacking (i.e., deconstructing existing technology for the purpose of creating knowledge), adapting (i.e., the freedom to use a technology for new purposes), designing (i.e., selecting components and ideas to solve problems), and creating (i.e., archiving contextual knowledge obtained through engaging in the process of making, as well as the actual tangible products) as part of an overall way of working with those interested in learning about science and technology.”

Many students are clueless when it comes to “making” and using hand tools. As such it will become import for you to monitor students on use and safety of hand tools and “making” processes, even after students have successfully met all requirements for using hand tools in your classroom or “Maker Space.”

Knowing how to handle tools is an essential skill everyone should have the ability to do correctly. Students will become more self-reliant, your supply budget money will stretch further, and students will develop a more in-depth knowledge of the concepts they are exploring when they are required to “make” their own experimental apparatus.

How to Use a HandsawBefore students put saw to wood, they need to determine what sort of handsaw they will need for the job. There are two basic designs of handsaws: the crosscut saw and the rip saw. Which one you use depends on whether you plan on cutting with or against the wood grain. Let’s take a closer look at the differences between the two saws and when you would use them.

Crosscut saw. If you’re cutting across the grain of the wood, you’ll want to use a crosscut saw. The teeth on a crosscut saw angle back and have a beveled edge. The teeth are also much smaller than those on a ripsaw. This design allows the saw to act like a knife-edge that cleanly


slices through the wood’s grain. The crosscut saw’s design also allows the saw to cut on both the push and pull stroke.

Rip saw. When you’re making a cut parallel to the direction of the grain of the wood, use a ripsaw. Unlike a crosscut saw, the teeth on a ripsaw don’t angle backwards nor are they beveled. Instead, the teeth bend left and right in an alternating pattern. This design allows each tooth to act like a chisel that chips away small pieces of wood on each push stroke. The chisel design ensures a clean cut as you saw along the grain. Also, unlike the crosscut saw, the rip saw only cuts on the push stroke, not on the pull stroke.

Typically, carpenters and woodworkers follow a few simple guidelines when using a hand saw.

Mark the cutline. Remember the timeless rule of carpentry: measure twice, cut once. Students should measure where they want a cut (twice of course) and draw a line marking where they want the cut to be. The line will act as a guide to help them get a straight cut.

Make the starting cut. When students make the first cut, have them use their thumb or the knuckle of their thumb on the hand holding the wood as a guide to ensure they cut along the cutline.

If they are using a crosscut saw, have them start their cut with the teeth nearest the handle. This will give them the best control. Make a few back cuts until they get a nice kerf (opening in the wood).

If they are using a ripsaw, have them start their cut with the finer teeth furthest from the handle (near the point of the blade). Make a few short draw strokes to get a kerf going.

Remind students to not start the cut right on the line they marked earlier with pencil. Instead, cut right next to the line on the waste side, or side they don’t want. It’s always better to have a piece of wood that’s a bit long, than a bit short. They can always sand the wood down to the pencil line if more precision is needed.

Angle the saw correctly. After they get their kerf going, students need to angle their saw correctly to get the best cut. This is typically between 45 and 60 degrees to the cutting surface. Some carpenters and woodworkers go so far as to break it down as follows: for crosscut saws, the proper angle is 45 degrees between the saw and wood and with ripsaws, it’s 60 degrees.

Hold your elbows close to your body. To counteract the natural tendency to angle the blade away from perpendicular, have students hold their


elbows close to their body when sawing. This will also help them prevent a twisting and tilting the blade, thus ensuring a nice, clean cut.

How to hold the saw. Students should grip the handle so that their forefinger extends along the side of the handle. This will help them “point” the saw along the line and ensures more accurate cuts. They should also hold on to the handle firmly, but not too tightly.

The stroke. After students have started the groove, a few short forward strokes will deepen the cut so they can move the hand they used as a guide away from the blade. Students will then be able to push the saw with an easy, free-running motion. Remind them to use long strokes so that each tooth does a fair share of the work. Short strokes can dull the saw and make it harder to cut.

Students should resist the temptation to bear down on the saw. It won’t do anything except tire them out. Let the saw do the work. If they feel like the saw isn’t cutting properly, the saw may be binding or it may be dull and in need of sharpening.

For straight cuts, use a guide. For some students, simply using the pencil line as their guide to cutting just doesn’t work. If students want to ensure that they get a true and square cut, have them place a small board, as a guide, along the pencil line and clamp it to the board they are cutting. The board will now act as their guide to keep the saw on the line. If available, a miter box can be another effective means of ensuring an accurate cut

Correcting veering. Even the best carpenters and woodworkers veer from the cut line occasionally. If this happens to students, tell them to avoid the natural tendency to twist and bend the saw blade so it gets back on track. This will only result in an uneven and rough cut. Instead, have students stop sawing and bring their blade back to the point where they veered off and start sawing again on the line.

Prevent binding. The biggest problem students will encounter, especially when they are cutting along the grain with a rip saw, is binding. Binding occurs when the kerf closes in on the saw. To prevent this, have students place a nail in their kerf. This will keep it open. Remind students that they may need to move the nail towards them as they saw.

Cordless Drill/Driver BasicsA cordless drill can handle all the drilling and driving needs of your students. A cordless drill gives students all the benefits of a drill without the hassle of a power cord or the fatigue associated with a hand held screwdriver.

A cordless drill typically comes with a battery and a charger, and some kits including a spare battery. For drills with lithium-ion batteries, you can keep a battery on the charger at all times so they will be ready whenever you have a project you want your students to complete. For other battery types, only charge the batteries as needed — this will help you get the longest life from your batteries.

A cordless drill also has forward and reverse settings with most having a variable speed trigger – the more pressure you put on the trigger, the faster the bit spins. There is also a high and low torque setting switch on top of the drill — higher speeds, low torque, are for drilling while lower speeds, high torque, are for driving. Most drills also have an adjustable clutch that gives you even more control over torque and helps you prevent overdriving.


The chuck of the drill is the piece that holds the bits in place. Most drills have a 3/8-inch chuck and can handle bits and accessories with a shank — the portion of the bit the chuck secures — 3/8 inch or smaller. Some larger bits have a reduced shank for use on smaller drills. Any task students are required to complete along with this curriculum will not require a bit with a shank larger than 3/8 inch.

If students have access to a 20 to 40-piece drilling and driving accessory kit, they will have everything you need to do all projects, challenges, and investigations associated with this curriculum.

Create a pilot hole. When driving screws into wood, it’s a good idea to drill a pilot hole first. Without pilot holes, screws tend to follow the grain of the wood, which results in crooked screws. Thus, pilot holes ensure that students drive the screw in straight.

Pilot holes also help prevent the wood from splinting as they drive the screw in. For small screws a pilot hole can be made with a small diameter drill bit. For larger sized screws and all screws in hardwood, drill a pilot hole using a drill bit with a counter sinking ability.

1. To drill a pilot hole, have students select a drill bit that is a little smaller than the tip of the screw.

2. They will insert a bit into your drill. 3. Have students hold their hand firmly around the chuck of the drill, and keeping it still while

running the drill in reverse, (#1 below) open the chuck (#2) or run the drill forward to close the chuck (#3).

4. When the chuck opening is big enough, have students insert the bit or driver. Remind students to not allow the bit or driver to fall to far into the chuck opening.

5. Have students hold their hand firmly around the chuck of the drill as they did before and run the drill in the forward motion until the bit is secured in the drill (#4).

6. Students should place the tip of the bit on the desired location for the pilot hole and ensure that the drill is straight and true with respect to the board orientation.

7. While pulling firmly on the trigger, students will use a firm and steady motion, to create their pilot hole. There should be little pressure required to drill a vertical pilot hole within a board because the weight of the drill will do most, if not all of the work. Horizontal holes will require a firm pressure while maintaining correct orientation with the board.


After students have drilled their pilot hole(s) they will attach their screwdriver bit and drive the screw in. Attachment of the screwdriver bit, and driving their screw, is accomplished the same way as inserting a drill bit and drilling a pilot hole.

Driving a screw with a screwdriver. Place the screw on the driver tip and hold both screw and tip together with the fingers of one hand. Align the screw tip with the pilot hole drilled previously and apply very little pressure on the driver while turning in a clockwise direction until the screw engages the wood.

When the screw’s thread engages with the wood, move fingers that were holding the screw in place to the screwdriver shank. Use these fingers as a guide to hold the tip directly in line with the screw. Apply enough pressure on the driver to keep it engaged with the screw.

Screwdrivers only do one job: drive and draw screws. No matter how much care you take with your screwdrivers, they’re bound to get worn or chipped. If you notice your screwdriver’s tip getting a bit rounded or chipped, avoid using it. You risk the screwdriver slipping from the screw and injuring your students.

You may be asking, “Can’t my student just use a cordless drill/driver to drive screws, without the hassle of pilot holes?” Indeed you can. However, be careful when doing this as they often provide more torque and power than you need, which, if you’re not careful, can result in stripping the screw and causing injury to the hand and other nearby objects. Using a pilot hole prevents these sorts of things because the screw will drive more easily and run true to the pilot hole.

When you are driving a screw, you will want to use a screwdriver bit in the end of your drill that matches the type of screw you are driving. Most likely, you will need to use a Phillip’s head drill bit but you may also choose square head and star (torx) head screws.

Some screwdriver bits come with a guide for holding screws in alignment with the bit. When using this type of driver bit, students will pull the sleeve over the screw to help keep it stable while they are driving the screw. The cover moves itself back as the screw goes into the surface. A screw guide isn’t necessary, but is extremely helpful with getting screws in straight and not having the screw fall off the bit.

How to read a Tape MeasureWhen it comes to building and craftsmanship, taking accurate measurements can be the difference between a great finished product and a subpar one. Luckily, with the proper approach, using a tape measure can be a quick, easy way to get you the information you need about your project. Knowing how to use and read a retractable measure and a traditional ribbon-style tape measure can be a major asset to anyone working with his or her hands.

1. Use the big, numbered markings for inches. On a tape measure labeled with standard units, the most prominent


marks are usually the one-inch marks. These are typically marked by long, thin lines and fairly large numbers.

Every 12 inches, there will often (but not always) be a foot marking. This is usually in a different color than the other markings — often red in contrast to the normal black markings. The numbers next to each inch mark will keep a continuous count while the foot markings may be followed by a repeat from 1 - 11. This can vary from tape measure to tape measure.

Note that the line next to the number marks each inch, not the number itself.

2. Use the bigger marks between two inch markings for half-inches. A half-inch mark is always centered between any two one-inch marks. It almost always has the second-longest marking (after the one-inch marks). There will be one half-inch mark between each one-inch mark, but it is important to remember that there are two half-inches per inch.

Note that, starting with half-inch marks, not all lines may be labeled with numbers. In this case, students will need to use the markings on either side to guide them. For example, the half-inch mark between inches three and four stands for 3 1/2 inches, even though it's not labeled.

3. Use the smaller lines between half-inches for quarter-inches. These markings are smaller than half-inches but usually bigger than the 1/8 and 1/16 inch marks around them. They are evenly spaced between each half-inch mark and one inch-mark. There are four quarter-inches in one inch.

Note that lines marking a quarter of an inch sometimes aren't any different in size from eighth-inch marks. In this case, students will need to remember that two eighths of an inch make a quarter.

4. The next smaller marks are for one-eighth-inches. These markings are centered between the inch marking and the quarter-inch marking, the quarter-inch marking and the half-inch marking, and so on. There are eight one-eighth inches per inch.

5. The tiny, densely-packed marks are for sixteenths of an inch. These are the shortest lines of all on most measuring tapes are the sixteenth-inch marks.

Catch the hooked end on one side of the object you're measuring.


Stretch the tape across your object. You can use one hand (or a friend) to hold the end of the tape in place as you pull it back. Let tape out until it stretches all the way across the distance you're measuring.

Read directly from the tape by looking at the point where the tape meets the end of the thing you're measuring or the desired measurement on the tape measure.

measurement A = 5 and 7/8 inches

measurement B = 6 inches

measurement C = 6 and 15/16 inches

The nearest number below the

end of the tape is your number of units you're measuring and the markings between this number and the one above it correspond to fractions of the unit.

6. Add the inch segments to determine total length. When you are measuring a length, getting an accurate value just means seeing where the tape lines up. Find the nearest inch before this point. Then, find the nearest half-inch before this point. Then, the nearest quarter-inch, and so on. Add up your inches and fractions of inches until you have an accurate measurement. This is a lot easier than it sounds — see below for an example.

Let's say that we've measured past the one-inch mark, past one quarter-inch mark, and past one eighth-inch mark. To find our measurement, we need to add:

1 (our inches) + 1/4 (our quarter-inches) + 1/8 (our eighth-inches).

Since there are two eighth-inches in a quarter-inch, we can rewrite this as:

1 + 2/8 + 1/8 = 1 3/8 inches.

Students may need assistance with adding fractions like 1/2, 1/4, 1/8, as they can be tricky for some students.

On most metric measuring tapes, centimeters are the most prominent markings. Centimeters are usually labeled with large lines and, next to each line, a number. As with inches, the line marks each centimeter, not the number itself.

Use the smaller markings between centimeters for 0.5 centimeters. Some (but not all) metric measuring tapes will have medium-sized marks evenly spaced between each centimeter mark. These marks are usually not labelled with a number.


The metric system is in base ten, which makes it much easier to work with decimals compared to standard measurements. For this reason, it's usually fine to refer to half-centimeter markings in decimal terms (i.e., 1 1/2 centimeters becomes 1.5 centimeters.)

Use the small, densely-packed markings for millimeters. There are ten millimeters in a centimeter (and, thus, one thousand in a meter.)

If your measuring tape doesn't have 0.5 centimeter markings, the fifth millimeter after each centimeter marks the 0.5 centimeter.

Add the centimeter segments to determine the total length. To measure with a metric measuring tape, first find the nearest centimeter before the distance you're measuring, then the nearest millimeter. You can use a 0.5 millimeter mark to help guide you if your measuring tape has them. Your measurement (in centimeters) will be a decimal where the tenths place is indicated by the millimeter marking. For example, see below:

Let's say that we measure past the 33 centimeter mark to the sixth millimeter marking. In this case, we can find our distance in centimeters like this:

33 + 0.6 = 33.6 centimeters

Some tape measures will have both standard units (feet and inches) and metric units.

Exploration: It’s a Balancing Act: LeversStudents will use hand tools to create an apparatus for investigating levers and determining the mathematical rule for equilibrium. Once students have constructed their testing apparatus and completed the initial experiment, it is expected that they will complete the Explore section and then be given additional time to go beyond the written material and test their own ideas.

Students will need assistance in analyzing data, making calculations, understanding their results and communicating their findings clearly and concisely. It is imagined that here is where your expertise will be most valuably used. By focusing on safety and encouraging the exploration process students should be able to engage with the material on a deeper level. With that in mind here are some things to consider:


1. Help students understand that the more effort they put into building their testing apparatus, the more accurate their data will be.

2. Help students only as required. The more they are able to do on their own, with little input from you, the more ownership they will put into their experiment and their learning

3. Cutting small pieces from larger stock is easier than cutting from small stock. Help students plan out the steps they will take to build their testing apparatus prior to the actual build.

4. Encourage students to create a diagram of their testing apparatus, including the forces acting at all points of the apparatus. This will assist students in understanding their data and making connections with the content.

5. Though there are numerous ways to build their testing apparatus, assist students in making one that is similar to the sample apparatus pictured in the experiment. This will not only allow them to learn skills that will be used in future experiments but will also assist you in working with multiple groups.

6. A Standard weight set is specified as an item used for weight due to the fact that most science classrooms have them, and they are readily available. However, any machine nut would work just as well, with the added bonus of not being round and viewed as a toy to be played with rather than part of the experimental process.

7. It is not expected that students complete the Explore section sequentially, rather the questions there are intended as starting points for sparking inquiry. Assist students by asking “What if” and “Have you thought about” questions to give them direction and starting points.

It is assumed that students are familiar with some sort of reporting style and format, based on your own classroom expectations. This experiment can easily be turned into a formal Lab Report, mini Science Fair, Classroom Presentation, or even Journaling. It is encouraged however to use a rubric similar to the one below as a means of assessing student learning and skill progress.

General Scoring Rubric: ExperimentsAssigning grades on a percentage scale may not work with all experiments. The following rubric describes six levels of student performance associated with all experiments students conduct. To use this 4-point scale, read the description of each level and decide which description most accurately reflects each experiment you grade.

A helpful strategy may be to create a file of past papers that you feel exemplifies each level of the rubric. These could be scanned and kept as a digital file or hard copy, whichever works best for you. You would then be able to make this file available to students as a guideline.

Online Resources

https://ips.iat.com/californiaEdition/students_edition2/test_prep/assets/u3c1_sample_quiz_key.pdf

http://static.nsta.org/files/pb243xweb.pdf

http://cmse.tamu.edu/documents/LittlegreenBookletv3.pdf

http://www.physicsclassroom.com/class/newtlaws/Lesson-2/Types-of-Forces

https://www.physicsclassroom.com/class/energy/Lesson-1/Definition-and-Mathematics-of-Work




http://www.physicsclassroom.com/class/newtlaws/Lesson-2/Types-of-Forces


http://static.nsta.org/files/pb243xweb.pdf

https://ips.iat.com/californiaEdition/students_edition2/test_prep/assets/u3c1_sample_quiz_key.pdf

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€¦ · Web viewMathematical Language Word problems describe science or math problems in words. To solve a word problem, you need to translate the language of words to the language