We have begun exploring our science topic for this term...energy. We plan to learn about the different types of energy and how energy can be transferred.
Today we looked at gravitational energy. Using tennis balls and larger balls we explored the energy of their fall by counting the number of bounces that happened when the ball hit the ground and by observing the height of the first bounce.
We discovered that the balls had a larger first bounce and a greater number of bounces when the ball was dropped by a taller person or when we were standing on something. Alex suggested that this was because the balls had a longer distance to fall, and she suggested that this means that the balls get more energy. Xavier suggested that the energy came from gravity.
We compared the energy from a tennis ball with the energy from a basketball. We found that the basketball had a larger bounce and had more bounces when it hit the ground than a tennis ball. We thought it was because it got more energy from gravity as it dropped. Miss Hall wondered why and asked us what we noticed about the tennis ball and the basketball when we compared them. Mahek said that the basketball was heavier. We all decided that heavier things fall faster than lighter things and more energy is transferred to the heavier things by gravity...this is why we think the basketball bounces higher and has a greater number if bounces than the tennis ball.
We then did something really exciting...we placed the tennis ball on top of the basketball and dropped them both at the same time. What do you think happened? Watch this video to find out what we discovered.
Heine wanted to know what would happen if we reversed the balls and had the basketball on top of the tennis ball. We predicted that the basketball wouldn't bounce really high or really fast like we had observed with the tennis ball. We thought this because the basketball is heavy and the tennis ball doesn't get much energy from gravity as it falls, so therefore there wouldn't be much energy to transfer to the basketball. We tested our hypothesis...we discovered that our hypothesis was correct! The basketball didn't bounce as high or as fast as the tennis ball. We noticed that it bounced much less than it did when it was dropped on it's own.
Could you repeat our experiment? Did you get the same results that we got? We would love to hear what you discovered!
