Answer :
The size of the force applied is 9760 Newtons.
To find the force applied to the merry-go-round, you can use Newton's second law,(F = ma). First, find the total mass of the system, which includes Kim, Katie, and the merry-go-round:
Mass of Kim: 45 kg
Mass of Katie: 36 kg
Mass of the merry-go-round: 163 kg
Add these masses together to get the total mass:
Total mass = 45 kg + 36 kg + 163 kg = 244 kg
Now, multiply the total mass by the acceleration to find the force:
F = ma = 244 kg × 40 m/s² = 9760 N
So, the size of the force applied is 9760 Newtons.