1. Bell Work: Centripetal Motion
If you increase the radius, the object will move ( faster / slower ).
If you increase the centripetal force, the object will move ( faster / slower ).
If you increase the mass, the object will move ( faster / slower ).
The _____ and _____ are directly related to the speed.
The ______ is inversely related to the speed.

2. How effectively a force causes rotation Symbol is tau (τ)
Torque
How effectively a force causes rotation
Symbol is tau (τ)

3. Fulcrum:
The point of rotation

4. Force should be perpendicular to the lever arm

6. Equation: OR τ = torque unit = N∙m
F = force perpendicular to the lever arm unit = N
d or L = length of lever arm unit = m

7. At equilibrium Fnet = 0 N At rest or spinning at a constant speed
All torques add up to zero
clockwise torque = counterclockwise torque

8. Balanced Torque
Girl’s torque = Boy’s torque
So, if the girl has more force (weight) her distance should be lower to balance the boy.

9. Example: Girl has a mass of 25 kg and is 120 cm from the fulcrum
Example: Girl has a mass of 25 kg and is 120 cm from the fulcrum. What is the boy’s mass if he is balanced 140 cm from the fulcrum?