Khan Academy on a Stick

Two-dimensional projectile motion

Let's escape from the binds of one-dimension (where we were forced to launch things straight up) and start launching at angles. With a little bit of trig (might want to review sin and cos) we'll be figuring out just how long and far something can travel.

Optimal angle for a projectile

This tutorial tackles a fundamental question when trying to launch things as far as possible (key if you're looking to capture a fort with anything from water balloons to arrows). With a bit of calculus, we'll get to a fairly intuitive answer.

Centripetal acceleration

Why do things move in circles? Seriously. Why does *anything* ever move in a circle (straight lines seem much more natural)? Is something moving in a circle at a constant speed accelerating? If so, in what direction? This tutorial will help you get your mind around this super-fun topic.