This is the fifth in a series of science projects for seventh grade. Students will learn how to get a rubber bouncy ball off of a table using the laws of gravity.
Use this project when teaching about gravity.
Have students share any knowledge they may have about gravity. Tell students that we can learn a lot about gravity through experiments. Let the students know that they are going to perform an experiment to see if they can use the laws of gravity to get a bouncy ball off of a table without picking the ball up or using their hands.
- Bouncy ball
- Mayonnaise jar
- Flat Surface
- Have students take a look at the jar, the ball, and the flat surface. Then ask the students to come up with a hypothesis that will explain how the ball will be taken off of the table without using any fingers. Make sure the students also list why they think their educated guess is correct. This should be written in the students science notebook.
- Have students take some time to experiment with the ball, the mayonnaise jar, and the table surface. If the students don't figure out how to use gravity to their advantage then you need to proceed to step three and show them how to do it. All successful and failed attempts should be recorded in the notebook.
- Set the ball down on the table top and put the open end of the jar over the bouncy ball. Start moving the jar around the ball in circles. Gradually increase speed until the ball is moving rapidly around in the jar.
- Slowly begin to lift the jar up off of the table. What happens to the ball? Does it fall out or does it keep spinning inside of the jar?
Have the students discuss the findings. Were they surprised by the experiment or did they fully understand gravity and predict what would happen? Ask the children to record their conclusions in their notebooks. Have some of the students share their hypothesis and discuss whether they were right or wrong.
by Stephanie Berghaeuser