The velocity of tennis racket after collision is 14.96m/s
<u>Explanation:</u>
Given-
Mass, m = 0.311kg
u1 = 30.3m/s
m2 = 0.057kg
u2 = 19.2m/s
Since m2 is moving in opposite direction, u2 = -19.2m/s
Velocity of m1 after collision = ?
Let the velocity of m1 after collision be v
After collision the momentum is conserved.
Therefore,
m1u1 - m2u2 = m1v1 + m2v2


Therefore, the velocity of tennis racket after collision is 14.96m/s
Hubble time in cosmology means the estimated age of the universe and the best calculation for it is T=1/H, where H is the Hubble constant
Answer:
-2.3 × 10^-9 Coulombs(C).
Explanation:
So, we are given the following data or information or parameters that is going to help us to solve the problem effectively and efficiently;
=> " the shuttle's potential is typically changed by -1.4 V during one revolution. "
=> " Assuming the shuttle is a conducting sphere of radius 15 m".
So, in order to estimate the value for the charge we will be making use of the equation below:
Charge, C =( radius × voltage or potential difference) ÷ Coulomb's law constant.
Note that the value of Coulomb's law constant = 9 x 10^9 Nm^2 / C^2.
So, charge = { 15 × (- 1.4)} / 9 x 10^9 Nm^2 / C^2.
= -2.3 × 10^-9 Coulombs(C).