It's called condensation. That is what that wetness on the outside of the cup is.
Answer:60 gm
Explanation:
Given
initial velocity of ball 
Force exerted by racquet 
time period of force 
final velocity of ball 
Racquet imparts an impulse to the ball which is given by



Answer:
F = N*μ or F =m*g*μ
Explanation:
The friction force is defined as the product of the normal force by the corresponding friction factor.
When a body is in equilibrium over a horizontal plane its normal force value shall be equal to:
![N = m*g\\where:\\m=mass [kg]\\g=gravity [m/s^2]\\N= normal force [N]](https://tex.z-dn.net/?f=N%20%3D%20m%2Ag%5C%5Cwhere%3A%5C%5Cm%3Dmass%20%5Bkg%5D%5C%5Cg%3Dgravity%20%5Bm%2Fs%5E2%5D%5C%5CN%3D%20normal%20force%20%5BN%5D)
if we simplify this formula more for a balanced body on a horizontal plane, we will have.

The first box is #3
the second box is #1
the third box is #2
the way I found this out because i read the definitions and found the key words in there.