A 0.62-kg ball...

Question

A 0.62-kg ball is moving at 3 m/s when it is hit by a bat, causing it to reverse direction and have a speed of 22 m/s. What is the change in the magnitude of the momentum of the ball?

Answer 1

In this case it is important to understand that the velocity of the body is changing its direction to the opposite. Change in the momentum

Δp = p₂ - p₁

Select the x-axis in the direction of the motion of the ball after the impact with the bat, then

Δp = p_2x - p_1x = mv₂ - (- mv₁) = mv₂ + mv₁ = m (v₁ + v₂)

After calculations, you will get

Δp = 15.5 N·s