What makes drills drill, DVD players play, and cars drive? If you said “motors,” you wouldn’t be wrong, but we’re talking about gears! In this BrainPOP movie, Tim and Moby will introduce you to the inner workings of just about every machine in your home! You’ll learn about gears’ basic purpose, and why most of them have teeth on their edges. Tim will show you the reason that big gears are often lined up with little ones, and how that can increase a machine’s power or speed. You’ll learn about mechanical advantage, the magnification of power created by high gear ratios, and about some of the other uses for gears, like reversing the direction of mechanical rotation, and changing the axis of motion. So put down that screwdriver--you don’t have to take apart your brother’s stereo to learn about gears. Just watch this movie!