First launch the video below. You will be asked to use your knowledge of physics to predict the outcome of an experiment. Then, close the video window and answer the questions on the right. You can watch the video again at any point.
Imagine that you replace the block in the video with a happy or sad ball identical to the one used as a pendulum, so that the sad ball strikes a sad ball and the happy ball strikes a happy ball. The target balls are free to move, and all the balls have the same mass. In the collision between the sad balls, how much of the balls’ kinetic energy dissipated?
___ None of it
___ Half of it
___ All of it
Now consider the collision between two happy balls described in Part A. How much of the balls’ kinetic energy dissipated?
___ None of it
___ All of it
___ Half of it