1. Do Now:
1. A toy car has a constant speed of 3 m/s around a small race track with a diameter of 6 meters.
What is the centripetal acceleration?
What direction is the acceleration and is it changing?
What direction is the velocity and is it changing?

2. Calculating Fc
Newton’s 2nd Law?
F = ma

3. Practice What is the centripetal force on a
2000 kilogram airplane making a
turn with a radius of 1000 meters
if it is moving at 300 meters per second?
Fc = mv2 / r
Fc = (2000 kg) (300 m/s)2 / (1000 m)
Fc = 180,000 N

4. Station Activity
Go to your station and attempt the following problem regarding circular motion!

5. Station 1 How far from the center of a merry-go-round
is a 500 kilogram horse that is traveling
at 3 meters per second if it experiences
a force of 3000 newtons?
Fc = mv2 / r
3000 N = (500 kg) (3 m/s)2 / r
r = 1.5 m
What is the period for the horse?
V = 2πr/T
T = 3.14 s

6. Station 2
A 1,000 kg car is making a turn onto a highway with a radius of 15 meters. The coefficient of friction is .8 between the tires and the road. How fast can the car go without skidding?

7. Station 3
A car travels around a flat circular track.  If the speed of the car is increased, the force required to keep it in the same circular path
A) decrease
B) Increase
C) remain the same
A 10 g rubber stopper is tied to a string and swung in a horizontal circle with a radius of 0.75 meters. The stopper makes 1 revolution in 1.5 seconds. Find the tension in the string (force) holding the stopper in its path.

8. Summary
1. What are some types of forces that can represent Centripetal Force?
Tension & Friction… Also Gravitation!
2. Sketch the direction of VC, aC and FC