- #1
Dejahboi
- 30
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Homework Statement
A 0.145-kg baseball is struck by a bat 1.20 m above the ground, popping straight up at 21.8 m/s. (a) What's the ball's kinetic energy when it leaves the bat? (b) How much work is done by gravity once the ball reaches maximum height? (c) Use your answer in part (b) to find that maximum height. (d) Find the work gravity does on the ball from when it's batted until it hits the ground. (e) Ignoring air resistance, use your answer in part (d) to find the ball's speed at the ground.
Homework Equations
K= 1/2mv2
The Attempt at a Solution
a) I used K=1/2mv2
so,
(.5)(.145 kg)(21.8 m/s)2= 34.45 J
b) I'm not sure how I did it but I got = -34.45 J
c)According to the free body diagram I drew, my initial velocity is 21.8 m/s, and Vf is 0. I'm not sure what equation to use here, I used Wg= -mgΔy but my answer does not match the book's answer.
As for the rest of the problem, I have no clue how to do it.