Can someone help me ?? :( A tennis ball moving with velocity 20 m s-1 towards a racquet. The ball is struck by the racquet so that it moves back in the opposite direction at 30 m s-1. If the racquet remains in contact with the ball for 0.02 s, find the average acceleration impacted by the racquet onto the tennis ball.
The answer : -2500 ms-2​

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Asailboat is traveling to the right when a gust of wind causes the boat to accelerate leftward at 2.5m/s2 for 4s. after the wind stops, the sailboat is traveling to the left with a velocity of 3.0m/s.assuming the acceleration from the wind is constant, what was the initial velocity of the sailboat before the gust of wind? answer using a coordinate system where rightward is positive.

Aforklift raises a box above the floor and does 2,000 j of work. if the forklift motor consumes 3,000 j of electrical energy from the battery to raise the box, what is the efficiency of the lift?