Bouncy Ball Energy

Bouncy Ball Energy

Learning Target: To determine the relationship between the gravitational potential, kinetic, total energy,
and time of a bouncy ball as it bounces.

Materials:
Borax Solution: Ball Mixture:
1 spoonful borax Food Coloring (optional)
6 spoonful’s Warm water 4 spoonful’s of glue
3 spoonful’s of cornstarch
2 Plastic cups
Popsicle stick (used to stir mixture)

Procedure
1. Label one cup 'Borax Solution' and the other cup 'Ball Mixture'.
2. Pour 6 spoonful warm water and 1 spoonful of borax powder into the cup labeled 'Borax Solution'. Stir the mixture to dissolve the borax. Add food coloring, if desired.
3. Pour 4 spoonful of glue and a few drops of food coloring (optional) into the cup labeled 'Ball Mixture' and
stir.
4. Add 1 spoonful of the borax solution you just made and 3 spoonful of cornstarch. Do not stir. Allow the
ingredients to interact on their own for 10-15 seconds and then stir them together to fully mix. Once the
mixture becomes impossible to stir, take it out of the cup and start molding the ball with your hands.
5. The ball will start out sticky and messy, but will solidify as you knead it. Run it under warm water for 5-10 seconds and continue to roll it in your hands until it solidifies.
6. Once the ball is less sticky, go ahead and bounce it!

Data Collection:
Take the mass of your bouncy ball (record on back of this sheet). Record a video of your bouncy ball when it
is dropped from a height of 2.5 meters from the ground. Make sure to include a meter stick in your video
frame, and to include the bounce back of the ball when it hits the floor. Email the video to group members.
We will upload and analyze the data next week.

Data Analysis:
Open Logger Pro and click on the “insert” tab and choose “movie”. Click on the button with red dots on it in
the bottom right corner of the video screen. This will enable you to analyze the motion in the movie. On the toolbar on the right side of the video window, select the fourth button down (yellow meter stick). This allows you to set the scale in the video and make measurements more accurate. Now click on one end of the 1 m scale bar and drag the line to the other end of the scale bar. When you release, a window will pop up asking you to enter distance. Set this to 1 meter. Click on the options tab at the top and choose “movie options.” At the bottom of the movie options window, change the number of frames the movie advances to 2. Increase the size of your video by clicking on a corner and dragging to enlarge it. Click second button from the top on the right side of the video screen (red dot in cross hairs). Pick the bottom of the ball to click on. Every time you click on the video screen, the video will advance two frames. Make sure you click on the same part of the ball every time. Collect data points until the end of the video.

Mass of the Bouncy Ball:_________

Convert the mass of the super bouncy ball. Record mass in kilograms here. ___________ kg

Record the maximum height of the super bouncy ball here. _____________ m

Sketch a position – time and a velocity – time graph for the bouncy ball as it travels across its’ path in the
space provided below. Consider only vertical motion (Y).
Draw energy bar charts for the bouncy ball at the top of each bounce and the bottom of each bounce.
1. Calculate the maximum potential energy (Eg) for the super bouncy ball at its’ highest point. Show your work in the space provided.
2. Using the data you collected, calculate the maximum kinetic energy (Ek) for the super bouncy ball. Indicate where the ball is at this moment in its travels. Explain your answer.