In being served, a tennis ball is accelerated from rest to a speed of 42.1 m/s. The average power generated during the serve is 2920 W. Assuming that the acceleration of the ball is constant during the serve, find the force acting on the ball.

Force F = 69.35 N

Explanation:

given data

Ball Initial speed u = 0

Ball Final speed v = 42.1 m/s

average power generate = 2920 W

solution

Power generate is express as

P=   ..............1

here W is work done and t is time

and work w = F × d

so

P=  

and we know speed v =  

so here

Power P = F × v

put here value and we get force

Force F =

Force F = 69.35 N

b.

explanation:

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.