unit1-ls1-studentedition-1.7

7/29/2019 Unit1-LS1-StudentEdition-1.7

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1.7 Explain

Learning Set 1

ACCIDENT CHALLENGE


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1.7 ExplainWhat factors affect energy transfer?

The McFarland City Council is excited to hear about the results of your investigation. They

hope to use the evidence from your investigation to write proposals that could reduce the

number of severe car accidents. However, before you can provide them with this information

you will need to make meaning out of your data by interpreting your results.

Part 1 of 3: Making Claims

Your first step to interpret your results is to identify trends and develop claims. Trends are

patterns in your data that you can see over several examples. A claim is a statement about

what those trends mean. For example, suppose you did a different experiment where you

varied the mass ofVehicle B, and you find that Vehicle B with less mass traveled a further

distance. This would be a trend. Your claim would then be a statement: When Vehicle B has

less mass, it travels a further distance when hit by Vehicle A. You will now review your own and

class data (including line graphs) to identify trends and make claims.

The citizens of McFarland have made many claims such as: the loaded trucks are causing more

severe accidents and the posted speed limit on Park Avenue is too high. However, these claims

are not considered valid, until they are supported by evidence.Evidence is the data that was

collected during your investigation and statements of evidence should contain measurements

or observations. An example of evidence to support the sample claim above would be: The

lower mass Vehicle B traveled a mean of 121 centimeters and the higher mass Vehicle B

traveled a mean of 75 centimeters after ten trials.

GROUP

GROUP

Identify a trend in your data to make one claim.

Record your trend and claim on Student Sheet 1.7.

Review your data from your investigation and write one to

two sentences that state your evidence to support your

claim on Student Sheet 1.7.


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1.7 ExplainPart 2 of 3: Add to your Understanding: Factors That Affect Energy Transfer

You have now stated a claim and supported it with evidence to interpret your results. However,

your claim and evidence was based on your model of accidents at the intersection. In order to

transfer your results from your model to the actual accident scene, you will need to develop an

understanding of the science knowledge that supports your claim and evidence. This is

important to be able to apply your claims to situations outside your model. Science

information provides the background for explaining how and why things happen the way they

do. Gaining this understanding will allow you to apply your knowledge from your investigation

to the intersection in the town of McFarland.

In collisions, energy is transferred from one object to another. During your investigation,

energy was transferred when the truck hit Vehicle B. This energy transfer is indicated by the

change in motion of Vehicle B. We can transfer this information to our car accidents in

McFarland. During each accident, energy was transferred from the strike vehicle to the target

vehicle. However, each accident had a different amount of energy transfer and that amount

determined the severity of the accident. The city council decided to investigate two factors

that would affect this energy transfer: mass and speed.

By investigating mass and speed, you were able to observe that Vehicle B varied its change in

motion when hit by the unloaded and loaded trucks at different speeds.

These changes in mass and speed affected the distance Vehicle B traveled. This distance is an

indicator of energy so therefore, we can state: Mass and speed are factors that affect the

energy of a moving object. In your investigation, mass and speed determine the energy ofthe

truck. When truckhas greater energy, it transfers a greater amount of energy to Vehicle B,

therefore causing a greater change in motion.

We have now determined that mass and speed affect the energy of a moving object. We have

also determined that there are conditions when the truck has a larger amount of energy and

when the truck has a smaller amount of energy. What conditions cause our truck to have more


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1.7 Explainenergy? How can we represent different amounts of energy using the factors of mass and

speed?

In your groups, you are going to discuss these questions and decide how to represent a large

amount energy and a small amount of energy in terms of mass and speed. Your group will then

draw a picture of an object with a large amount of energy and picture of an object with a small

amount of energy. In each picture, represent speed and mass to show the amount of energy of

the object.

When your group has finished drawing your picture, give it to your teacher to post in the front

of the classroom. Your teacher will now facilitate a class discussion on these representations of

different amounts of energy. As you examine the objects representing of different amounts of

energy, think about these questions to participate in the class discussion:

What do you notice about the objects representing larger amount of energy? What do you notice about the objects representing the smaller amounts of energy? How are mass and speed expressed in these pictures?

How does mass affect energy?

You may have drawn a larger, heavier object to represent a larger amount of energy. In your

investigation, you may have discovered that the loaded truck caused Vehicle B to have a

greater change in motion when tested at the same speed as the empty truck. As this change in

motion is an indicator of energy, the loaded truck has more energy than the empty truck at the

same speed. Even though both trucks were the same size and shape, the loaded truck had more

energy. Therefore, we can state: Mass has a direct relationship to the amount of energy;

when the mass of an object is increased and all other conditions remain the same, the

GROUP

Draw an object with a large amount of energy and an

object with a small amount of energy on Student Sheet 1.7.

In each picture, show the speed and mass of the object.


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1.7 Explainamount of energy of a moving object increases. In order to demonstrate this concept visually,

you will watch the following video, which shows the difference in energy transfer in collisions

between objects of different masses.

Watch Video 7

How does speed affect energy?

In your drawing of an object with a large amount of energy, you may have tried to show that it

was moving fast. As you collaborated with your classmates and examined your line graph data,

you may have noticed the trend that when both the loaded or unloaded truck was released at

higher heights (greater speeds), Vehicle B had a greater change in motion after the collision.

This distance is an indicator of energy, so you can conclude that by increasing the speed of the

truck, you increased the energy of the truck. Therefore we can state: Speed has a direct

relationship with energy; if there is an increase in speed and all other conditions remain the

same, the amount of energy of an object increases. In order to demonstrate this concept

visually, you will watch the following video, which shows the difference in energy of objects

moving at different speeds.

Watch Video 8

This scientific information will support your claim and evidence from your investigation to

develop an explanation that will allow the McFarland City Council to write proposals to reduce

the severity of the accidents. You will now record this scientific information to support your

claim and evidence.

STUDENTWrite one or two sentences or phrases in the Science

Content Knowledge box on Student Sheet 1.7.


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1.7 ExplainPart 3 of 3: Update the Challenge Organizer

In Section 1.1, you learned that an engineer is a person who applies their science and math

knowledge to develop a solution to a problem. You also learned that recording information is

very important in engineering. Before we move on to addressing accident challenge, we will

return to the challenge organizer to record what we have learned. You will complete this

individually and then share your updates with the class.

Your teacher will now ask some students to share this information with the class to update the

class Challenge Organizer.

Complete What we have learned column on your

individual Challenge OrganizerSTUDENT


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