Suppose a zookeeper must shoot a banana from a banana cannon to a monkey who hangs from the limb of a tree. This particular monkey has a habit of dropping from the tree the moment that the banana leaves the muzzle of the cannon. The zookeeper is faced with the dilemma of where to aim the banana cannon in order to hit the monkey. If the monkey lets go of the tree the moment that the banana is fired, then where should she aim the banana cannon? To ponder this question, first consider a scenario in which there is no gravity acting on either the banana or the monkey. What would be the path of the banana? Would the banana hit the monkey?
As is obvious from the animation above, the banana moves in a straight line path in the absence of gravity. As such, a banana aimed directly at the monkey will hit the monkey. In the absence of gravity, the banana moves in a straight line path (and does not experience any downward acceleration) and the monkey does not fall once he lets go of the tree. But what if there were gravity? Where should the zookeeper aim her banana cannon to successfully hit the monkey? Suppose that the zookeeper aims above the monkey's head. Would this lead to success?
To further study the Monkey and Zookeeper dilemma and see additional animations, click on one of the following links.
The Monkey and The Zookeeper
Throw above the Monkey with Gravity On
Throw at the Monkey at a Fast Speed with Gravity On
Throw at the Monkey at a Slow Speed with Gravity On
Click on any of the above links to explore the zookeeper's dilemma.
For more information on physical descriptions of motion, visit The Physics Classroom. Detailed information is available there on the following topics:
Acceleration of Gravity
Acceleration of Gravity and the Independence of Mass
Characteristics of a Projectile's Trajectory