# 2016 AP Physics 1 Free Response #2

TLDRIn this educational video, Alan from Bothell STEM discusses a hypothetical experiment to test the elasticity of ball collisions. He suggests using a high-speed camera and a meter stick to measure the bounce height and compares it to the drop height to determine energy conservation. The data should ideally show a linear relationship, with deviations indicating non-elastic collisions. Alan also addresses possible experimental errors and offers free homework help on Twitch and Discord for further learning.

###### Takeaways

- π Alan from Bothell STEM is coaching AP Physics students on free response questions.
- π The discussion focuses on testing the hypothesis of perfectly elastic collisions using a new kind of toy ball.
- π€ A student suspects that no collision can be perfectly elastic, especially at higher speeds.
- π§ The student proposes that collisions might be close to perfectly elastic at low speeds but deviate at higher speeds.
- π The experiment involves bouncing the ball from various heights to measure drop and bounce heights.
- π Equipment suggested includes a high-speed camera, a meter stick, and a measurement tape.
- π The data will be represented graphically to compare potential energy before and after the collision.
- π A perfectly elastic collision would show equal potential energy before and after the bounce on the graph.
- π Any deviation from a straight line on the graph would indicate a loss of energy during the collision.
- π The student's experiment aims to analyze whether the collisions are consistent with the hypothesis of elasticity.
- π€ A graph or table showing more energy after the collision than before would violate the conservation of energy principle.
- π Alan offers free homework help on Twitch or Discord for students with questions in math and physics.

###### Q & A

### What is the main topic of the video script?

-The main topic of the video script is designing an experiment to test the hypothesis about the elasticity of collisions of a ball with a hard surface.

### What is the student's hypothesis regarding the ball's collisions?

-The student's hypothesis is that collisions are very close to being perfectly elastic at low speeds but deviate more from perfect elasticity as the collision speed increases.

### What type of equipment would be used in the experiment according to the script?

-The equipment mentioned includes a high-speed camera, a meter stick or measurement tape, and possibly a school Physics Laboratory setup.

### How would the student measure the height of the ball's bounce?

-The student would use a high-speed camera to record the ball's motion and a measurement tape to measure the drop height and bounce height.

### What quantities would be measured in the experiment?

-The quantities measured would include the potential energy before and after the collision, which is represented by the product of mass (M), gravity (G), and height (H).

### How would the data be represented in the experiment?

-The data would be represented in a graph or table, comparing the potential energy before and after the collision.

### What would a perfectly elastic collision look like on the graph?

-A perfectly elastic collision would be represented by a straight line where the potential energy before and after the collision is equal (y = x).

### What would the graph show if the experiment violated the conservation of energy?

-If the conservation of energy is violated, the graph would show that the potential energy after the collision is more than before the collision, indicating an increase in energy.

### What does the student conclude if the graph or table shows non-elastic behavior for low-speed collisions?

-The student would conclude that something went wrong with the experiment because non-elastic behavior at low speeds would violate a basic physics principle.

### How would the student test the hypothesis comparing low versus high-speed results?

-The student would test the hypothesis by comparing the ratio of potential energy after collision to before collision as a function of pre-collision speeds, expecting it to stay near one for low speeds and deviate for high speeds.

### What additional service does Alan offer for students who have homework questions?

-Alan offers free homework help on Twitch or Discord for students who have questions about math and physics or just want to learn and hang out.

###### Outlines

##### π¬ Designing an Experiment to Test Elastic Collisions

In this paragraph, Alan from Bothell STEM coach introduces a hypothetical scenario where a student is skeptical about the perfect elasticity of a new kind of toy ball. The student suggests that low-speed collisions might be close to perfectly elastic, but as the speed increases, the collisions deviate from this ideal. Alan proposes an experiment to test this hypothesis using common school Physics Laboratory equipment. The plan involves bouncing the ball from varying heights to measure the drop and bounce heights, using a high-speed camera and a measuring tape. The data will be represented in a graph or table to compare the potential energy before and after the collision, which will help determine if the collisions are perfectly elastic. A deviation from a straight line in the graph would indicate energy loss during the collision, thus disproving the hypothesis of perfect elasticity.

##### π Analyzing Experimental Data for Energy Conservation

Alan continues the discussion by addressing how the student should analyze the experimental data. The student is expected to plot a graph comparing the mechanical energy before and after the collision with a hard surface. If the graph shows that the energy after the collision is more than before, it would violate the principle of conservation of energy, indicating an error in the experiment. Alan suggests that a correct graph would show the ratio of post-collision to pre-collision energy near one for low-speed collisions, and then deviate as the speed increases, demonstrating the loss of elasticity at higher speeds. He also mentions offering free homework help on Twitch or Discord for those interested in further learning about math and physics.

###### Mindmap

###### Keywords

##### π‘Elastic Collision

##### π‘Potential Energy

##### π‘Speed

##### π‘High-Speed Camera

##### π‘Meter Stick

##### π‘Energy Conservation

##### π‘Graph

##### π‘Experiment

##### π‘Hypothesis

##### π‘Physics Laboratory

##### π‘Free Response Question

###### Highlights

Alan introduces the continuation of the AP Physics 2016 free response questions.

Discussion of a new toy ball advertised to bounce perfectly elastically off hard surfaces.

A student's hypothesis that no collision can be perfectly elastic is presented.

The student's observation that collisions are close to perfectly elastic at low speeds but deviate at higher speeds.

Designing an experiment to test the hypothesis about the ball's collisions.

Equipment available in a school Physics Laboratory is mentioned for conducting the experiment.

Suggestion to measure the ball's drop height and bounce height to determine energy loss during collisions.

Use of a high-speed camera and a meter stick for precise measurement of the ball's motion.

Explanation of how the data will be represented in a graph or table to analyze energy conservation.

Comparison of potential energy before and after the collision to test for perfect elasticity.

Description of how a deviation from a straight line in the graph would indicate non-perfect elasticity.

The student's immediate conclusion that something went wrong with the experiment due to unexpected results.

Explanation of how the graph or table should show elastic behavior for low-speed collisions.

Discussion of a basic physics principle that seems to be violated in high-speed collisions.

Proposal of a conceptually plausible plan to measure the ball's collision positions.

Suggestion to use a meter stick to measure heights and record the ball's motion against a wall.

Application of data analysis to test the hypothesis by comparing low versus high-speed results.

Proposal to graph the ratio of energy conservation as a function of pre-collision speeds.

Alan's offer of free homework help on Twitch or Discord for those interested in math and physics.

###### Transcripts

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