Answer:
The angular momentum and angular velocity are 1.134 kg.m²/s and 174.5 rad/s.
Explanation:
Given that,
Moment of inertia 
Torque = 21 N.m
Time dt = 54 ms
(a). We need to calculate the angular momentum
Using formula of torque


Where, dL = angular momentum
t = time
= torque
Put the value into the formula


(b). We need to calculate the angular velocity of the disk
Using formula of angular velocity




Hence, The angular momentum and angular velocity are 1.134 kg.m²/s and 174.5 rad/s.
Answer:
Explanation:
Given
Distance between two balls is 
mass of first ball 
mass of second ball 
Gravitational force between two forces is given by

Substituting values
where G=gravitational constant


Kinetic energy is transformed to potential energy