Answer
given,
mass of ball, m = 57.5 g = 0.0575 kg
velocity of ball northward,v = 26.7 m/s
mass of racket, M = 331 g = 0.331 Kg
velocity of the ball after collision,v' = 29.5 m/s
a) momentum of ball before collision
P₁ = m v
P₁ = 0.0575 x 26.7
P₁ = 1.535 kg.m/s
b) momentum of ball after collision
P₂ = m v'
P₂ = 0.0575 x (-29.5)
P₂ = -1.696 kg.m/s
c) change in momentum
Δ P = P₂ - P₁
Δ P = -1.696 -1.535
Δ P = -3.231 kg.m/s
d) using conservation of momentum
initial speed of racket = 0 m/s
M u + m v = Mu' + m v
M x 0 + 0.0575 x 26.7 = 0.331 x u' + 0.0575 x (-29.5)
0.331 u' = 3.232
u' = 9.76 m/s
change in velocity of the racket is equal to 9.76 m/s
14 ms is required to reach the potential of 1500 V.
<u>Explanation:</u>
The current is measured as the amount of charge traveling per unit time. So the charge of electrons required for each current is determined as the product of current with time.

As two different current is passing at two different times, the net charge will be the different in current. So,

The electric voltage on the surface of cylinder can be obtained as the ratio of charge to the radius of the cylinder.

Here
, q is the charge and R is the radius. As
and R =17 cm = 0.17 m, then the voltage will be

The time is required to find to reach the voltage of 1500 V, so


So, 14 ms is required to reach the potential of 1500 V.