Jawaban:

We can use the principle of conservation of momentum to solve this problem. Since there are no external forces acting on the ball-racket system, the total momentum before and after the collision must be equal.

Let's first find the momentum of the ball before the collision:

p_before = m*v_before

where

m = 100 g = 0.1 kg (mass of the ball)

v_before = 10 m/s (velocity of the ball)

p_before = 0.1 kg * 10 m/s = 1 kg m/s

During the collision, the racket applies a force of 120 N for 0.02 s, which changes the momentum of the ball. The change in momentum is given by:

Δp = F*t

where

F = 120 N (force applied by the racket)

t = 0.02 s (time of contact)

Δp = 120 N * 0.02 s = 2.4 kg m/s

The final momentum of the ball can be calculated as:

p_after = p_before + Δp

p_after = 1 kg m/s + 2.4 kg m/s = 3.4 kg m/s

Finally, we can find the velocity of the ball after the collision using the equation:

p_after = m*v_after

v_after = p_after / m

v_after = 3.4 kg m/s / 0.1 kg = 34 m/s

Therefore, the velocity of the ball after the collision is 34 m/s, which is not one of the answer choices. We may have made an error in our calculations or assumptions, or the answer choices may not be accurate.