Answer:
The angular speed of the record is 3.36 rad/s.
Explanation:
Given that,
Mass of record= 0.10 kg
Radius = 0.10 m
Angular speed = 4.7 rad/s
Moment of inertia 
Mass of putty = 0.020 kg
We need to calculate the angular speed
Using law of conservation of momentum



Put the value into the formula


Hence, The angular speed of the record is 3.36 rad/s.
D.) All of the above ...........
Answer:
784 J
Explanation:
Work is force times distance.
W = Fd
W = mgd
W = (40 kg) (9.8 m/s²) (2 m)
W = 784 J
D
the waves are in phase. crests come together to form bigger crests hence higher amplitude
Yes they are balanced because if it has 10 Newtons to the right and then someone pushes 5 Newtons to the left and then another 5 then that means there is 10 Newtons left and 10 Newtons right