We like Monkeys. We like guns. Put them together and you get a...
Monkey gun. Oh yes. But it's not what you think.
No, the purpose of the monkey gun is not to shoot primates. Instead, it is a mental exercise to demonstrate the independence of vertical and horizontal motion. Although, shooting monkeys would be... no, I couldn't.
The exercise runs along these lines: Imagine hunters trying to kill a monkey with a dart and a blow gun. Since the dart will fall as it travels, one would have to aim above the monkey to hit it. Figuring out how high above the monkey to aim is difficult, so our hunters employ a different strategy. The idea is to scare the monkey off the branch right when the dart is shot so that the dart and the monkey fall the same distance.
There are two parties: One to shoot the blow-gun and one to scare the monkey down from the tree. The trick is to figure out the timing betwean the two and all the applicable angles in order that the vectors of the monkey and dart coincide in their fall.
The mathematics regarding the ballistics and trajectory are deceptively simple.. or misleadingly simple, depending on how you look at it and how good you are with math. Wanna kill the monkey? Try this:
bullet trajectory
yb = vy t - 0.5 g t^2
monkey trajectory
ym = H - 0.5 g t^2,
....where H is the original height of the monkey.
...beats the hell out of that damn "Punch the Monkey" banner add.