Projectile Motion (Ball thrown Hortizonally)

[talaroue]

Homework Statement

A ball thrown horizontally at 22.47 m/s travels a horizontal distance of 43.15 m before hitting the ground. From what height was the ball thrown?

Homework Equations

Vfy=Viy-g(delta t)
yf=yi+Viy(delta t)-.5g(delta t)^2
yf=yi-(Vfy^2-Viy^2)/2g

The Attempt at a Solution

Since its thrown horizontally does it arc above the intial position or does it just start its decent so instead of being a upside down "u" shape it just has like a backwards "r" shape?

 

[nickjer]

Never heard of those shapes before. Knowing that there is no acceleration in the horizontal direction, you can get the time it takes to hit the ground with horizontal velocity and displacement.

Then you know that the initial y-velocity is 0 m/s. So just solve a kinematic equation for the height knowing the time it takes to fall to the ground with 0 initial velocity.

 

[talaroue]

haha it was a bit unorthidox method of looking at it but I understand it now thanks.

 

[nickjer]

No problem.