Posted June 5, 2008on:
When I teach projectile motion, I like to do exercises where the students have to predict the results and then perform the experiment. One of my favorite toys is something called Stomp Rockets. They aren’t as easy to find as they were 10 years ago. They are plastic rockets that are launched from a tube and plastic bladder that you stomp on. If you set the angle to around 45° and jump up and come down hard with your heals, you can launch a rocket the length of a football field. If you launch them straight up, you can use a stopwatch to determine the maximum altitude. This is obviously an outside activity, but there are also foam rockets that we have launched in the gym. Outside is more fun.
I built a supersized cardboard protractor to set the launch angle and I had to rebuild the launch stand because it just wasn’t sturdy enough. The challenge is that you can’t get the same launch pressure twice, so the lesson has to be generic enough to get the point across without getting accurate results. We tend to experiment with the relationship between the launch angle and the distance.
I’ll put some pictures here some day, I haven’t done the activity in quite a while.