I had a similar problem to this. I came across this website and it helped me through it.
http://hyperphysics.phy-astr.gsu.edu/hbase/airpw3.html#c2
You can click on "Details about calculation" and it will give a little more explanation. Then you can click "More detail on calculation" and it...
Homework Statement
A cannonball is fired with initial speed v0 at an angle 30° above the horizontal from a height of 38.4 m above the ground. The projectile strikes the ground with a speed of 1.3v0. Find v0. (Ignore any effects due to air resistance.)
Homework Equations
v= Vo + at...