VEX IQ Curriculum - Simple Machines & Motion
Simple Motion (more fully known as Simple Harmonic Motion) is what happens when an object moves in a non-complex periodic way. This means that:
- The object experiences a force that moves it
- The movement occurs, reaching some maximum value
- The object returns to its “original” conditions
- The process repeats
Let’s take the example of a pendulum and consider what happens. A pendulum is defined as a body suspended from a fixed point so that it can swing back and forth under the influence of gravity as a force.
When a pendulum is started, it swings (accelerates) down under the influence of gravity. Gravity is the attraction between two masses, such as the earth and an object on its surface. At the bottom of its arc, the pendulum then swings up on the other side. It continues to move up (and decelerate) until it stops. The pendulum then begins to swing back down, reaching some maximum velocity at the bottom of its arc before swinging back up to where it began. The pendulum has gone through one complete cycle of its motion, and because it is a repetitive cycle, it can be said to be simple harmonic motion. Friction (the force that resists motion through the rubbing of one object against another) will eventually stop the pendulum, but not before several cycles have passed.