A tennis ball approaches a racquet with a momentum of 5 kgm/s and bounces back with a momentum of 6 kgm/s in the opposite direction after the collision with the

Question

Help, I can't understand this question?

Answer 1

Although the question is incomplete, I will assume you want the change in the linear momentum of the ball.  Assuming the inbound direction is positive,

 

Δp = p_f - p_i = (-6 - 5) kg m/s = -11 kg m/s