Circular Motion A brief intro.

Uniform Circular Motion

• UCM is the movement of an object or particle trajectory at a constant speed around a circle with fixed radius, r.

• Velocity is tangential to the edge of the circle at any point. This means velocity vectors are constantly changing. (in direction)

• Acceleration is directed inward, toward the center of the circle. Again, it is constantly changing. (in direction) This is called centripetal acceleration.

Velocity around a circle

• Since velocity is equal to distance divided by time, we simply need to adjust this to the terms of a circle.

• Distance = circumference

• Time = period: how long it takes for one rotation to be completed

• So velocity = circ./period

Formulas for centripetal acceleration