Motion and Design Motion and Design Lesson 4Lesson 4

Testing the Motion of Vehicles Testing the Motion of Vehicles Carrying LoadCarrying Load

MaterialsMaterials

Timer per groupTimer per group Record Sheet 4-A: Graphing Date copy Record Sheet 4-A: Graphing Date copy

per studentper student Standard vehicle per groupStandard vehicle per group Bookend per groupBookend per group String with hooks per groupString with hooks per group Colored pencilsColored pencils 16 small washers in a cup per group16 small washers in a cup per group 2 blocks of wood per group2 blocks of wood per group

OverviewOverview Adapt vehicle to carry a load of blocks and test Adapt vehicle to carry a load of blocks and test

how the weight of the load affects the vehicle’s how the weight of the load affects the vehicle’s motion.motion.

Will grasp the concept that the heavier the load, Will grasp the concept that the heavier the load, the slower the average speed of the vehicle.the slower the average speed of the vehicle.

Will discuss and graph results and observations.Will discuss and graph results and observations.

Develop an understanding of the relationships Develop an understanding of the relationships among force, mass, and change in motion.among force, mass, and change in motion.

BackgroundBackground Mass – amount of material in an objectMass – amount of material in an object

Weight – amount of force gravity exerts on an Weight – amount of force gravity exerts on an object’s massobject’s mass

On the Moon, people weigh 1/6 as much as on On the Moon, people weigh 1/6 as much as on Earth, but their mass is the same.Earth, but their mass is the same.

Force affects motion of lighter and heavier Force affects motion of lighter and heavier vehicles.vehicles.

The wood used in this unit is light enough that a The wood used in this unit is light enough that a vehicle carrying 2 blocks should move when vehicle carrying 2 blocks should move when pulled by 10 small washers. However, if a pulled by 10 small washers. However, if a wooden block contains knots, it may be more wooden block contains knots, it may be more dense, and thus heavier, than other blocks.dense, and thus heavier, than other blocks.

Using the TimerUsing the Timer

Round to the nearest whole number.Round to the nearest whole number. Start timer when object begins to move.Start timer when object begins to move. Stop timer when weight hits the floor.Stop timer when weight hits the floor. Demonstrate and practice using the timer.Demonstrate and practice using the timer. Time the motion of a student moving Time the motion of a student moving

across the classroom.across the classroom. What are some examples of motion that What are some examples of motion that

we measure with time? (foot race, we measure with time? (foot race, swimming meets, horse race, car trip)swimming meets, horse race, car trip)

How would adding blocks to your How would adding blocks to your vehicle change the way the vehicle vehicle change the way the vehicle moves? moves?

Write predictions in notebook.Write predictions in notebook.

Hold up 2 blocks and vehicle. How Hold up 2 blocks and vehicle. How could you adapt your vehicle to hold could you adapt your vehicle to hold 2 blocks of wood while moving?2 blocks of wood while moving?

To make this investigation fair, each group To make this investigation fair, each group will attach the blocks in the same manner.will attach the blocks in the same manner.

Testing the motion of Vehicles Testing the motion of Vehicles Carrying a LoadCarrying a Load

Set up the Falling-weight system as you did in Lesson 3.Set up the Falling-weight system as you did in Lesson 3.

Add 2 blocks to your vehicle. Squeeze the crossbars to Add 2 blocks to your vehicle. Squeeze the crossbars to make certain the blocks are held in place.make certain the blocks are held in place.

Make certain that 1 end of the string is attached Make certain that 1 end of the string is attached to the vehicle and the other end is threaded to the vehicle and the other end is threaded through the opening in the bookend.through the opening in the bookend.

Pull the vehicle back until the hook is at the top Pull the vehicle back until the hook is at the top edge of your work space.edge of your work space.

One partner hold vehicle in place.One partner hold vehicle in place.

Place 10 small washers on the hook. Place 10 small washers on the hook.

Hang the weights over the edge of your work Hang the weights over the edge of your work space. Make sure the hook is not stuck on the space. Make sure the hook is not stuck on the table edge.table edge.

Let go of the vehicle. If it does not move, Let go of the vehicle. If it does not move, tap it slightly.tap it slightly.

Can the 10 washers move the vehicle?Can the 10 washers move the vehicle?

If the vehicle still does not move, add If the vehicle still does not move, add more small washers, one at a time.more small washers, one at a time.

Stop adding washers when the vehicle Stop adding washers when the vehicle begins to move, even slightly, across the begins to move, even slightly, across the table.table.

Count your washers and write the number on Count your washers and write the number on Record Sheet 4-A. Use this number of washers Record Sheet 4-A. Use this number of washers throughout this investigation. Do not change the throughout this investigation. Do not change the number of washers.number of washers.

Get your timer.Get your timer.

Pull the vehicle back again until the hook is at the Pull the vehicle back again until the hook is at the top edge of the table. top edge of the table.

When you are ready to begin set the timer to 0.When you are ready to begin set the timer to 0.

As you let go of the vehicle, start the timer. (If As you let go of the vehicle, start the timer. (If the paper clip gets stuck on the edge of the table, the paper clip gets stuck on the edge of the table, start over.)start over.)

Stop the timer when the falling weights touches Stop the timer when the falling weights touches the floor.the floor.

Talk with your group about your Talk with your group about your vehicle’s motion.vehicle’s motion.

How did the blocks affect how the How did the blocks affect how the weighted string pulled your vehicle?weighted string pulled your vehicle?

Will use a timer to measure how long it Will use a timer to measure how long it takes your vehicle to move.takes your vehicle to move.

Keep the number of washers the same for Keep the number of washers the same for each trial. Change only the load carried each trial. Change only the load carried by the vehicle.by the vehicle.

Color a circle above the number on the Color a circle above the number on the line plot that represents the number of line plot that represents the number of seconds it took your vehicle to travel a seconds it took your vehicle to travel a distance equal to the height of your work distance equal to the height of your work space while carrying a load of wooden space while carrying a load of wooden blocks.blocks.

Vehicle + 2 Block (green dots)Vehicle + 2 Block (green dots) Put 2 blocks between the crossbars.Put 2 blocks between the crossbars. Squeeze the crossbars so the block stays in place.Squeeze the crossbars so the block stays in place. Pull the vehicle back until the hook is at the top Pull the vehicle back until the hook is at the top

edge of the table. edge of the table. Reset your timer to 0.Reset your timer to 0. Let go of the vehicle.Let go of the vehicle. Stop the timer when the weights hit the floor. Stop the timer when the weights hit the floor. Color your results on the graph green.Color your results on the graph green. If you get the same time as an earlier trial, color a If you get the same time as an earlier trial, color a

circle directly above the circle from the other circle directly above the circle from the other trial.trial.

Do this 5 times altogether.Do this 5 times altogether.

Vehicle + 1 Block (blue dots)Vehicle + 1 Block (blue dots) Only use 1 block between the crossbars.Only use 1 block between the crossbars. Squeeze the crossbars so the block stays in place.Squeeze the crossbars so the block stays in place. Pull the vehicle back until the hook is at the top Pull the vehicle back until the hook is at the top

edge of the table. edge of the table. Reset your timer to 0.Reset your timer to 0. Let go of the vehicle.Let go of the vehicle. Stop the timer when the weights hit the floor. Stop the timer when the weights hit the floor. Color your results on the graph blue.Color your results on the graph blue. If you get the same time as an earlier trial, color a If you get the same time as an earlier trial, color a

circle directly above the circle from the other circle directly above the circle from the other trial.trial.

Do this 5 times altogether. Do this 5 times altogether.

Vehicle (red dots)Vehicle (red dots) Remove all the blocks.Remove all the blocks. Pull the vehicle back until the hook is at Pull the vehicle back until the hook is at

the top edge of the table. the top edge of the table. Reset your timer to 0.Reset your timer to 0. Let go of the vehicle.Let go of the vehicle. Stop the timer when the weights hit the Stop the timer when the weights hit the

floor. floor. Color your results on the graph red.Color your results on the graph red. If you get the same time as an earlier trial, If you get the same time as an earlier trial,

color a circle directly above the circle from color a circle directly above the circle from the other trial.the other trial.

Do this 5 times altogether.Do this 5 times altogether.

DiscussionDiscussion

What did you observe when testing What did you observe when testing various loads or blocks?various loads or blocks?

How did the vehicle move when it was How did the vehicle move when it was loaded with 2 blocks?loaded with 2 blocks?

How did the motion of the vehicle change How did the motion of the vehicle change when you removed 1 block? How did it when you removed 1 block? How did it change when you removed both blocks?change when you removed both blocks?

What did you think would happen if you What did you think would happen if you added a 3added a 3rdrd or 4 or 4thth block to the vehicle? block to the vehicle?

DiscussionDiscussion When the vehicle carried no blocks, what When the vehicle carried no blocks, what

was left to influence its motion or the was left to influence its motion or the weight of the vehicle?weight of the vehicle?

What can you conclude about the effects What can you conclude about the effects of load (such as blocks) on a vehicle’s of load (such as blocks) on a vehicle’s motion? (The heavier the vehicle, the motion? (The heavier the vehicle, the longer the vehicle takes to respond to a longer the vehicle takes to respond to a force.)force.)

What situations at home or in school may What situations at home or in school may be similar to what you tested in this be similar to what you tested in this lesson?lesson?

After InvestigationAfter Investigation

Describe approximately how much Describe approximately how much time it took your vehicle in each trial time it took your vehicle in each trial to move the given distance.to move the given distance.

By taking repeated measurements By taking repeated measurements and selecting a value from these and selecting a value from these measurements, you can get a more measurements, you can get a more representative measure of the time it representative measure of the time it took your vehicle to move than if you took your vehicle to move than if you measure only once.measure only once.

ExtensionsExtensions

Investigate how the position of the Investigate how the position of the vehicle’s load might affect your results. vehicle’s load might affect your results. Try stacking blocks horizontally instead of Try stacking blocks horizontally instead of vertically or a front loading vehicle instead vertically or a front loading vehicle instead of a back loading one.of a back loading one.

Imagine you are transporting an important Imagine you are transporting an important shipment across the continent. What will shipment across the continent. What will the shipment be? What is the destination? the shipment be? What is the destination? Why must the shipment be delivered? Why must the shipment be delivered? How will you transport it? After you have How will you transport it? After you have delivered the load, how will the return trip delivered the load, how will the return trip be different?be different?

Extensions ContinuedExtensions Continued Use timer to measure the elapsed time of various Use timer to measure the elapsed time of various

events, such as the length of their lunch period, events, such as the length of their lunch period, the amount of time it takes someone to run the amount of time it takes someone to run across the playground, the time it takes for a car across the playground, the time it takes for a car to travel between 2 telephone poles, or how fast to travel between 2 telephone poles, or how fast a fish swims the length of the fish tank.a fish swims the length of the fish tank.

Research and write about various load-bearing Research and write about various load-bearing vehicles. Including how they are different from vehicles. Including how they are different from each other.each other.

Display photographs of various load-bearing Display photographs of various load-bearing vehicles. Using materials from home, such as vehicles. Using materials from home, such as shoe boxes and empty spools to create a model shoe boxes and empty spools to create a model of one of the displayed vehicles.of one of the displayed vehicles.

The End!!!The End!!!