Projectile Motion baseball hit at ground level

[rasikan]

Homework Statement

A baseball is hit at ground level. The ball is observed to reach its maximum height above ground level 3.0 s after begin hit. And 2.5 s after reaching this maximum height, the ball is observed to barely clear a fence that is 320 ft from where it was hit. How high is the fence?

Homework Equations

i think I can use these equation
x-x0=vx0t
y-y0=vyot-gt^2/2

The Attempt at a Solution

I have no clue about this question

 

[hage567]

I would start with the fact that you know the time to maximum height. Since it is parabolic motion, you can use this to find the maximum height since you know that at the instant of maximum height, Vy=0. See if that helps.

 

[arunma]

Another consequence of parabolic motion is that the ball reaches its maximum height in half the time it takes to reach the ground again.

 

[anantchowdhary]

Another consequence of parabolic motion is that the ball reaches its maximum height in half the time it takes to reach the ground again.

This can also be proved by using
v-u/t=a