1. Rotational Motion Chapter 7 & 8

2. Centripetal Force • Newton’s 2nd Law • Whenever there is acceleration there is a force to cause it • F = ma • Fc = mac

3. WARNING!!! • Centripetal Force is not a new, separate force created by nature! • Some other force creates centripetal force • Swinging something from a string  tension • Satellite in orbit  gravity • Car going around curve  friction

4. Conceptual Problem • What affects Fc more: a change in mass, a change in radius, or a change in speed? • A change in speed since it is squared and the others aren’t.

5. Vertical Circular Motion Your Fc is your net force

6. When calculating at vertical points…

7. Conceptual Example • During a circus trapeze act, a man hangs from a bar and swings his partner from their arms. Which is harder to do: hold the partner still under the bar, or to swing the partner under the bar? • Swing because not only is there gravity, but there is also centripetal force. • What provides the Fc? • Tension their arms

8. Why did the red car cut over?

9. Angle of embankment

10. Free Body Diagram