1. Circular Motion
Chapter 10

2. 10.1 Rotation & Revolution Turning around an internal axis is rotation
Turning around an external axis is revolution
Earth does both!!

3. 10.2 Rotational Speed
Where do you move the fastest? On the out side of a merry-go-round or on the inside?

4. Answer:
**It depends on what type of speed you are talking about

5. Question:
At an amusement park, you and a friend sit on a large rotating disk. You sit at the edge and have a rotational speed of 4 RPM and a linear speed of 6 m/s. Your friend sits halfway to the center. What is her rotational speed? What is her linear speed?

6. Answer:
her rotational speed is 4 RPM and her linear speed is 3 m/s

7. Tangent A tangent is a line that touches a circle at one point
So for circular motion, tangential speed is the same as linear speed

8. Rotational Speed
What’s the difference between rotational and tangential speed?
Rotational speed is the # of rotations per unit of time
Tangential speed is linear speed along a circular path

9. Tangential speed
Tangential speed is directly proportional to the radial distance x rotational speed or
V ~ rω

10. 10.3 Centripetal Force Means “aiming at center” it is an inward force
The force you feel when are pushed to the wall in a ride. (force of the wall on you)
Constant acceleration

11. Centripetal Force
Example

13. Six Flags

14. 10.4 Centrifugal forces Means “center fleeing”
The force that pushes you away from the curve.

15. Centrifugal Force
It is Inertia

16. 10.6 Centrifugal Force Revealed
It is a result of rotation.
It is not part of an interaction
It is not a true force