Projectile ball velocity physics problem

[Tiger15]

Homework Statement

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You see a 10m tall building nearby and you want to throw a snowball up and onto its roof. You notice a telepone line running accoss the possible path of your snowball; the telephone line is 20 m off the ground and is 5 m in front of the building (measured horizontally). You decide to throw the snowball so that is just goes over the telepohne line and just reaches the roof of the building. HOW FAR from the building should you stand and with what initial velocity should you throw the ball?

Homework Equations

The Attempt at a Solution

 

[Filip Larsen]

Welcome to PF. You should remember also to explain what equations you think are relevant and what you have done so far to find a solution. It is customary not to provide help unless people show that they have already made an effort to solve their homework and it also makes it easier to provide you with a small push in the right direction if we know where you are stuck.

 

[hepcatdsm]

2: Relevant equations:

1)F=m*a
2)a = dv/dt
3)v = dx/dt
g=9.81m/s^2

3:
you need two equations(x,y) for your system that considers: distances(x,y), gravity and intial speed(x,y)

gravity only acts in Y
nothing acts in X (assuming drag is neglected)