A tennis ball of mass 10.0 g bounces vertically on a concrete floor. The ball strikes the floor at 20.0 m s–1 and rebounds at 15.00 m s–1. 5. A. What is the change in speed of the ball as it bounces? Δv = v1-v2 = 20ms-1 - 15ms-1 Δv = 5ms-1 B. What is the change in velocity of the ball as it bounces? Δv = v1 - v2 = 20ms-1 – (-15ms-1) Δv = 35ms-1 Does that depict the difference between speed and velocity as speed is a scalar quantity it doesnt have direction therefore when calculating (in this case) is a positive value, but when calculating the change in velocity because it is a vector quanitiy it has a direction ( negative because it's going in the opposite direction as the initial drop) so it has a negative value? Im not sure if this is correct. thank you.