"The Monkey and the Coconut" is a classic thought experiment used to illustrate the effect of the gravitational force on a projectile.
A coconut tree is growing in the middle of a small river. Two monkeys arrive at the bank and notice a small ripe coconut about to fall into the river. In order to get the coconut, the monkeys make a plan: On the count of three, the first monkey will shake the tree, while the other will jump across the river and catch the coconut as it falls, landing on the far bank.
How should the second monkey aim her jump in order to catch the coconut?