Abaseball player throws a ball straight up and catches it 3.0 s later. if the ball accelerates at 9.85 m/s2 down, at what velocity did he throw the ball?

With constant acceleration, we have

At the end of the throw, the ball's velocity is equal to its initial velocity in magnitude, but in the downward direction so its sign is opposite and . Then

= initial pressure

= final pressure = 2

= initial volume

= final volume = /4

= initial temperature = 20 c = 20 + 273 = 293 k

= final temperature = ?

using the equation

the answer is c. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads.