Question Detail
Question
A 50-kilogram student threw a 0.40-kilogram ball with a speed of 20 meters per second. What was the magnitude of the impulse that the student exerted on the ball?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Impulse equals the change in momentum of the ball. The ball starts from rest (presumably in the student's hand) and reaches a speed of 20 m/s. J = Δp = mΔv = 0.40 kg × 20 m/s = 8 Ns. The mass of the student is irrelevant.
Hint
Impulse on the ball is its change in momentum. Focus on the ball's mass and velocity change.