1. Angular Momentum
Section 10-9

2. Momentum
p = mv L = Iω

3. Impulse

4. Conservation of Angular Momentum
The total angular momentum of a rotating body remains constant if the net external torque acting on it is zero.

5. Figure Skater
54. A figure skater during her finale can increase her rotation rate from an initial rate of 1.0rev every 2.0s to a final rate of 3.0rev/s. If her initial moment of inertial was 4.6kg∙m2, what is her final moment of inertia? How does she physically accomplish this change?

6. Springboard Diving

7. Example 10-13 – Clutch Design
MA=6.0kg, MB=9.0kg, R0=0.6m
MA is accelerated from rest to ω1=7.2rad/s in Δt=2.0s.
Find angular momentum of MA.
Find torque required to get to ω1.
MB is initially at rest but free to rotate without friction. MB falls vertically so it is firmly in contact with MA. The two rotate together and angular velocity is considerably reduced from ω1 to ω2. (c) Why does this happen, and what is ω2?

8. Ex10-15 Running on circular platform
60kg person at edge of 6.0m-diameter circular platform with I = 1800kg∙m2. The platform is initially at rest.
When the person begins running at a speed of 4.2m/s (with respect to the ground) around the edge, the platform begins to rotate in the opposite direction. Calculate the angular velocity of the platform.

9. Spinning bicycle wheel