- #1
SPH4UJS
- 3
- 0
Homework Statement
A baseball pitcher throws a ball vertically upward and catches it at the same level 4.2s later
a) with what velocity did the pitcher throw the ball?
Homework Equations
The Attempt at a Solution
I put this into givens
t = 4.2 s
displacement = 0 m if the ball goes up and then comes back at the same level I figured it has a displacement of 0
acceleration = -9.81 m/s
Vf = 0 m/s since it goes up then reaches a climax and it was already thrown with an initial velocity that you are trying to find
so I decided to use the vf = vi + a(t)
so.. then I rearranged it so that it was
vf - ( a ) ( t ) = vi
which gave me
-(-9.81)(4.2) = vi
and then I got 41.2 but that's not the right answer :S so I am not sure if its just that I am using a wrong equation or that I have the wrong givens I don't know exactly what I am doing wrong please point me in the right direction.