2. Example 8-15 v1 = 2.4 m/s r1 = 0.8m r2 = 0.48 m v2 = ? I1ω1 = I2ω2
 ω2 = ω1 (r2)2/(r1)2 , ω1 = (v1/r1)
v2 = r2ω2 = r2(v1/r1)[(r2)2/(r1)2] = v1 (r1/r2)
v2 = 4.0 m/s

3. Angular Quantities are Vectors!

4. Conservation of Vector Angular Momentum

5. Conceptual Example 8-17 Conservation of angular momentum!!
Linitial = Lfinal
L = - L + Lperson
 Lperson = 2 L
Demonstration!

6. Translation-Rotation Analogues & Connections
Displacement x θ
Velocity v ω
Acceleration a α
Force (Torque) F τ
Mass (moment of inertia) m I
Newton’s 2nd Law ∑F = ma ∑τ = Iα
Kinetic Energy (KE) (½)mv (½)Iω2
Work (constant F,τ) Fd τθ
Momentum mv Iω
CONNECTIONS: v = rω, atan= rα
aR = (v2/r) = ω2r , τ = rF , I = ∑(mr2)

7. Problem 58
Demonstration!!