1. An object with the 轉動慣量 of 2克 m2 rotates at 1 rad/s. 是什麼 角動量 of the object?
已知：
慣性矩 (I) = 2 kg m2
角速度 (ω) = 1 rad / s
招募： 角動量 （L）
解決方案：
Formula of angular momentum :
L = I ω
L = 角動量 (kg m2/s), I = 轉動慣量 (kg m2), ω = 角速度 (rad/s)
角動量：
L = I ω = (2)(1) = 2 kg m2/s
2. 一個2-kg cylinder pulley with radius of 0.1平方米 rotates at a constant angular speed of 2 rad/s. What is the angular momentum of the pulley ?
已知：
質量 of pulley （米） = 2kg
Radius of pulley (r) = 0.1 m
角速度 (ω) = 2 rad/s
招募： 角動量
解決方案：
Formula of moment of inertia for solid cylinder :
I = 1/2 m r2
我= 轉動慣量 (kg m2), m = 質量 (kg), r = 半徑 （米）
轉動慣量：
I = 1/2 (2)(0.1)2 = (1)(0.01) = 0.01 kg m2
The angular speed :
L = I ω = (0.01)(2) = 0.02 kg m2/s
3. A 2-kg uniform sphere with radius of 0.2平方米 rotates at 4 rad/s. What is the angular momentum of the ball.
已知：
質量 球的 （米） = 2 kg
Radius of ball (r) = 0.2 m
角速度 (ω) = 4 rad/s
招募： 角動量
解決方案：
Formula of moment of inertia for uniform sphere :
I = (2/5) m r2
I = moment of inertia (kg m2), m = mass (kg), r = 半徑 （米）
The moment of inertia for uniform sphere :
I = (2/5)(2)(0.2)2 = (4/5)(0.04) = 0.032 kg m2
The angular momentum of sphere :
L = I ω = (0.032)(4) = 0.128 kg m2/s
4. A 1公斤 particle rotates at a constant angular speed of 2 rad/s. What is the angular speed if the radius of circle is 10厘米。
已知：
質量 物件 （米） = 1kg
The radius of circle (r) = 10 cm = 10/100 = 0.1 m
角速度 (ω) = 2 rad/s
招募： 角動量
解決方案：
Formula of moment of inertia for particle :
I = 先生2 = (1)(0.1)2 = (1)(0.01) = 0.01 kg m2
Angular momentum :
L = I ω = (0.01)(2) = 0.02 kg m2/s
