Science Assessment ~ Items ~ AP063002

A class is studying how light from the sun can be used to power machines. They construct a toy car with a solar panel on the top of it.

Watch the video to see what happened to the car when light was allowed to shine on the car and when light was not allowed to shine on the car.

1. Write your observations in the table below. You should describe what happens when light shines on the car and when light was blocked and does not shine on the car.

Observations when light from the sun shines on the car	Observations when light from the sun does not shine on the car

2. The teacher asks the students to make sense of their observations by thinking about how energy is moved from place to place. What evidence is there from the video that energy was transferred from the sun to the car? Why does this evidence support the idea that energy was transferred from the sun to the car?

Next, the class takes a closer look at the car's parts. They see that the car has a solar panel and wires that connect the solar panel to an electric motor. The electric motor is attached to the back wheels.

Image of a toy car with a solar panel (DesignBoom)

The students attach a device that measures electric current to the wires. (Electric current is measured in milliamps.) They measure how much current flows in the wires when light was allowed to shine on the solar panel and when light was not allowed to shine on the solar panel. Below is a table summarizing their measurements.

	Light from the sun shines on the solar panel	Light from the sun does not shine on the solar panel
Current in the wires	10 milliamps	0 milliamps

3. Again, the teacher asks the students to make sense of these observations by thinking about how energy is moved from place to place. What evidence is there from the table that energy was transferred from the sun to the car? Why does this evidence support the idea that energy was transferred from the sun to the car?

4. Which of the following models best represents how energy was transferred between the sun, solar panel, and electric motor when light was allowed to shine on the car?

Arrows in the models show the direction of energy transfer and the labels on the arrows show how energy moved between the electric motor, solar panel, and sun.

A.
B.
C.
D.

Details
Performance
NGSS

Topic: 3D Energy Tasks
Scoring Rubric: Q1; 1. For “Observations when light from the sun shines on the car,” the student indicates that the car started moving or implies the car started moving (i.e., the car was able to drive).

2. For “Observations when light was blocked and could not shine on the car,” the student indicates that the car slowed down and/or stopped.; Q2; 1. Student cites evidence

When light from the sun shined on the car it moves.

When light was blocked and not allowed to shine the car slowed down.

Note: If the student writes that the car only moves when light shines on it, they receive credit for both cases

2. Student states or uses a general science idea

Energy is present whenever there are moving objects (i.e., the car has more energy when it is moving than when it stops). [links speed and energy]

3. Student uses reasoning to link evidence and general science idea

The car moves when the light shines on it, which means it has more energy. This energy came from the sun.; Q3; 1. Student cites evidence

A current was detected when light shined on the car.

A current was not detected when the light was blocked.

Note: If the student writes that a current flows only when light shines on the car, they receive both points.

2. Student states or uses a general science idea

Energy can be moved from place to place through electric currents (i.e., the current in the wire is transferring energy from the solar panel to the engine). [links electric current and energy transfer]

3. Student uses reasoning to link evidence and general science idea

The current is detected when the light shines on the car, which means energy is being transferred from the solar panel to the motor/wheels to make the car move. This energy came from the sun.; Q4; Student selects answer choice B

B.

Percent of Points Earned

Chart showing distrubtion of responses for Item AP063002

Points Earned

	Avg. Earned	Possible	Percent
Q1	1.71	2	85%
Q2	1.03	3	34%
Q3	0.61	3	20%
Q4	0.72	1	72%

Overall Task Difficulty

	Total Points Earned	Total Points Possible	Total Percent
	4.07	9	45%

n = 392

Note: The total percent is a weighted average based on the total number of points earned divided by the total number of points possible.

Science and Engineering Practices: SEP2 Develop and/or use models to describe and/or predict phenomena.
SEP3 Make observations and/or measurements to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution.
SEP6 Use evidence (e.g., measurements, observations, patterns) to construct or support an explanation or design a solution to a problem.
Crosscutting Concepts: CC4 A system can be described in terms of its components and their interactions.
CC5 Energy can be transferred in various ways and between objects.
Disciplinary Core Ideas: PS3.A Energy can be moved from place to place by moving objects or through sound, light, or electric currents.
PS3.B Energy is present whenever there are moving objects, sound, light, or heat. When objects collide, energy can be transferred from one object to another, thereby changing their motion. In such collisions, some energy is typically also transferred to the surrounding air; as a result, the air gets heated and sound is produced.
PS3.B Light also transfers energy from place to place.