Day 117: Bowling Ball Impulse
Trying to explore concrete examples of the momentum-impulse theorem BEFORE busting out equations and derivations. I thought of the classics: bungee cords, airbags, etc. But most kids think of those things as force absorbers rather than time extenders.
Then I remembered the bowling balls and mallets. Stop a rolling ball in 2 mallet traps. Then stop the ball in 4 taps. What's the same? Different?
Then I asked the kids to model the before, during, and after: motion map, velocity-time graph, force-time graph, and a momentum bar for the ball. Again, the visual appeared: each mallet tap took momentum away from the ball. Weaker forces took away less momentum, and therefore more taps over a longer time were needed to stop the ball. Some kids even saw a possible connection between the force-time graph and the momentum bar graph. We'll explore that connection tomorrow.