Final answer:
The magnitude of the average force exerted on the ball by the wall is 30 N.
Step-by-step explanation:
The magnitude of the average force exerted on the ball by the wall can be calculated using the impulse-momentum equation.
Impulse = change in momentum
Since the ball bounces back with the same speed, the change in momentum is given by: m * change in velocity = 0.10 kg * (0 - 3.0 m/s) = -0.30 kg·m/s
The force exerted on the ball by the wall is equal to the impulse divided by the time of contact: F = -0.30 kg·m/s / 0.01 s = -30 N
Therefore, the magnitude of the average force exerted on the ball by the wall is 30 N.