The classic shoot-the-monkey demonstration, anew

Daniel Rosenberg (whom you will see in the Ig Nobel Prize ceremony next month) and his colleagues at the Harvard Science Center staged and shot (anew!) this brief video of a classic physics demo:

This is a demonstration of the independence of the horizontal and vertical components of the velocity of a projectile. Often referred to as “the monkey and hunter,” the problem is the following. Suppose a hunter (at ground level) points a gun directly at a monkey hanging from a branch high in a tree. The monkey, being very intelligent, does not want to be shot. It knows that light travels faster than bullets and reasons that, if it lets go of the branch the instant it sees the gun being fired, it will fall down far enough before the bullet reaches its destination and thus miss its mark. What happens? Unhappily the monkey does not know that the gravitational acceleration is the same for all falling objects (whether they be bullets or monkeys) and thus the bullet falls the same distance as the monkey, hitting it on the way down. Neither the bullet’s initial velocity nor the distance between hunter and monkey is relevant to the final outcome, and affects only the height above the ground where bullet meets monkey….