Answer:

Explanation:
We are given that
Radius,r=2 m
Moment of inertia,I=250
Angular velocity,
Mass of child,m=20 kg
We have to find the new moment of inertia of the merry go round.
New moment of inertia ,
Using the formula


Hence, the new moment of inertia of the merry -go-round=
I believe it requires 1,314,718 J. Have a great day =D
Answer:
B) 35 W
Explanation:
Force applied by child = 75 N = F
Distance travelled by child = 42 m = d
Time traveled for is 1.5 min = 1.5×60 = 90 seconds = t
Work done by the child
W = Fdcosθ
⇒W = 75×42cos0
⇒W = 3150 Joule
Power is defined as work done per unit time

∴ The average power generated by the child is 35 W
Complete Question
(A) What is the maximum tension possible in a 1.00- millimeter-diameter nylon tennis racket string?
(B) If you want tighter strings, what do you do to prevent breakage: use thinner or thicker strings? Why? What causes strings to break when they are hit by the ball?
The tensile strength of the nylon string is 
Answer:
A
T = 471.3 \ N
B
To prevent breakage the thickness of the string is increased
String breakage when the racket hit the ball is as a result of the string not being thick enough to withstand the increase in tension
Explanation:
From the question we are told that
The diameter is
The tensile strength of the nylon string is 
Generally the radius is mathematically evaluated as

=> 
=> 
The cross sectional area is mathematically represented as

=> 
=> 
Generally the tensile strength of nylon is mathematically represented as

Where T is the tension on the maximum tension on the string
So

=> 
=> 
Form the equation above we see that

So if the tension is increased to prevent breakage the thickness of the string is increased(i. e the cross-sectional area )
String breakage when the racket hit the ball is as a result of the string not being thick enough to withstand the increase in tension