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Homework Statement
A tennis ball has a mass of 0.057 kg. A professional tennis player hits the ball hard enough to give it a speed of 44 m/s (about 99 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (44 m/s). As indicated in the diagram below, high-speed photography shows that the ball is crushed about d = 2.1 cm at the instant when its speed is momentarily zero, before rebounding.
What is the magnitude of the average force exerted by the wall on the ball during contact?
Homework Equations
pf=pi+Fnet([tex]\Delta[/tex]T
The Attempt at a Solution
For this problem, we also had to solve for the average speed from contact to 0, [tex]\Delta[/tex]T, and mag. of Fgrav.
vavg= 22 m/s in x direction
[tex]\Delta[/tex]T= 9.5455e-4 sec
mg=.5586 N
I got those right. Now for my attempt at the force.
I know that
pf=pi + Fnet [tex]\Delta[/tex]T.
and
pavg= m(vavg)
= (.057)(22)
= 1.254
I assumed that Favg=pavg/[tex]\Delta[/tex]T
and got
Favg= (1.254)/(9.5455e-4)
= 1313.708
That's not right.
Help would be greatly appreciated!