I believe the answer is option A
I think it's the last one
Answer:
F=480.491 N
Explanation:
Given that
mass ,m = 22 kg
Angular speed ω = 40 rev/min

ω =4.18 rad/s
The radius r= 1.25 m
We know that centripetal force is given as
F=m ω² r
Now by putting the values in the above equation we get

F=480.491 N
Therefore the centripetal force on the child will be 480.491 N.
Answer:
The correct option is (d). "3x stronger".
Explanation:
The force between two charged particle is given by :

If one charge is tripled, 
New force will be :

It means if one of the charges were to triple in strength, then the force will become 3 times of the initial force.