1. Circular Motion

2. Demo 1: Newtonian Mountain Newton's Cannon on a Mountain Newton's Cannon on a Mountain What force causes circular motion? What happens if you shoot it too fast? What is the direction of the velocity at each point?

3. Demo 2: Object on Turntable What force causes circular motion? What happens when it goes too fast?

4. Demo 3: Spinning Object on String What force causes circular motion? What happens when you let go of the string?

5. A car moves around a circular track at 40 mph. Are the speed and velocity of the car constant? Speed is constant Velocity is not constant because direction is changing. If the velocity is changing then the car is accelerating.

6. centripetal Latin, “center seeking”

7. Centripetal Acceleration (a c ) The acceleration of a rotating or revolving object that is directed toward the center of its circular path. a c = v 2  tangential velocity r  radius r  radius

8. Centripetal force (F C ) A force that causes an object to take a circular path Directed toward the center of the circular path NOT a new force, old forces such as F g, F f, F N, F a, tension, etc. act as a centripetal force

9. F net = m a F c = m a c F c = m a c F c = m v 2 F c = m v 2 r