1. November 2
AP Physics

2. Momentum Test return

3. In:
What makes objects move in a circle?

4. Objective: To begin our study of circular motion. Success criteria:
Discover the variables of centripetal force, and be able to do centripetal force and acceleration problems.

6. Discovery Lab: Circular motion
Using the circular motion device, discover everything you can about circular motion.
List your discoveries:

7. What did we find out?

8. Period (T) is the time it takes to go around once.
Frequency ( f ) the number of times it goes around in one second
T=1/ f

9. Centripetal acceleration
Always toward the center
ac= v2 r

10. “Center seeking” force
Centripetal force:
“Center seeking” force
Fc= mv2 r

11. V=d/t Distance = 2πr Time=T (period) So……. V= 2πr T
Tangential Speed
V=d/t Distance = 2πr Time=T (period) So……. V= 2πr T

14. Problem
A 2.1 m rope attaches a tire to an overhanging tree limb. A girl swinging on the tire has a tangential speed of 2.5 m/s. If the magnitude of the centripetal force is 88 N, what is the girl’s mass?

15. A bicyclist is riding at a tangential speed of 13
A bicyclist is riding at a tangential speed of 13.2 m/s around a circular track. The magnitude of the centripetal force is 377N, and the combined mass of the bicycle and rider is 86.5 kg. What is the track’s radius?

16. A dog sits 1.5 m from the center of a merry-go round and revolves at a tangential speed of 1.8 m/s. If the dog’s mas is 18.5 kg, what is the magnitude of the centripetal force on the dog?

17. A 905 kg car travels around a circular track with a circumference of 3
A 905 kg car travels around a circular track with a circumference of 3.25 km. If the magnitude of the centripetal force is 2140 N, what is the car’s tangential speed?

18. Practice Problems:

19. What makes objects move in a circle?
Out:
What makes objects move in a circle?