Max height of projectile using energy conservation

[frenchy7322]

Homework Statement

find max height of a projectile traveling at 40 m/s 60 degrees from the horizontal using conservation of energy

Homework Equations

KEi + PEi = KEf + PEf?

The Attempt at a Solution

couldnt attempt. (I know I can't be given the answer, but even just the proper equation would be handy, thanks!)

 

[Dick]

Split the initial velocity v into x and y component, vx and vy. At launch the KE is (1/2)*m*v^2, at max height, it only has a vx component, so KE=(1/2)*m*(vx)^2. Set the KE difference equal to the PE difference m*g*h and solve for height h.