ok, heres the prob: A 21.0 kg cannon ball is fired from a cannon with a muzzle speed of 1100 m/s at an angle of 37.3° with the horizontal. A second ball is fired at an angle of 90.0°. Use the law of conservation of mechanical energy to find (b) the total mechanical energy at the maximum height for each ball. Let y = 0 at the cannon. in (a), i had to find the height for each ball, which i did using ( mv^2/2 ) - mgh = 0 i found the first ball to be 2.27e4 m/s (using 1100sin37.3) and the second ball to be 6.17e4 now i can find the mech energy do you use ( mv^2/2 ) + mgh = Mech E (i simplified changed in PE and changed in KE in the above equation) and then add the two Mech Energies?