Answer: 
Explanation:
Given
Mass of child 
speed of child is 
Moment of inertia of merry go round is 
radius 
Conserving the angular momentum

Answer : Option C) copy the movements performed during the activity.
Explanation : Arm circles are an effective dynamic stretch for swimmers because they copy the movements performed during the activity.
During swimming when the arm circles are performed it stretches the triceps brachii, loosens the shoulder blade and stretches the side muscles.
Often many people are observed to perform this arm circles stretch without bringing the elbow behind the head, but especially for swimmers, this increases the stretching length and reduces stress while swimming.
Answer:
Friction is a kind of force between two object when we rub or slide its surfaces together
for ex: when you rub the matchbox you get fire which is the result of friction
Explanation:
thats all i know
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