How do i find the the distances above ground?

[lane99]

Homework Statement

A hot air balloon is ascending straight up at a constant speed of 7 m/s. When the balloon is 12 m above the ground, a gun fires a pellet straight up from ground level with an initial speed of 30 m/s. Along the paths of the balloon and the pellet there are two places where each of them has the same altitude at the same time. How far above ground level are these places?

Homework Equations

The Attempt at a Solution

dont really know how to solve this and have a test tomorrow so any help is greatly appreciated, thanks

 

[gneill]

Hi lane99, Welcome to Physics Forums.

What have you tried so far? You need to show some effort before others can help you, that's in the forum rules. At the very least you can write down a list of equations that you think might be relevant for this kind of problem.