Day 23: Bowling Balls, Mallets, and Motion

This is a variation on the classic broom ball activity. Using a mallet, students make the bowling ball do various motions (speed up, slow down, constant speed, sharp left turn, go in a circle, etc.).

Broomball handout

Why a mallet instead of the broom, you ask?

1. Students come to us with an impulsive view of force. I have found they have trouble with “constant, steady, continuous force” such as from the broom.
2. Much easier to see that the ball speeds up / slows down when hit by the mallet and that it travels with constant velocity when not being hit.
3. Can easily move from impulsive force to a constant force by making the tapping intervals smaller and smaller.

Students draw motion diagrams and add red arrows to show when and how they tapped the ball. Then we look for a pattern and come up with a casual model for force and motion. Later we use dueling fan carts to revise the model to include NET force.