Physics
posted by Lisa on .
A cannon is fired from a cliff 190 m high downward at an angle of 21° with respect to the horizontal. If the muzzle velocity is 34 m/s, what is its speed (in m/s) when it hits the ground?

final KE= intial KE+initialPE
1/2 m v^2=1/2 m 34^2 + mg*190
solve for v 
but i don't have m...

divide both sides by m. It divides out. You don't have to know the mass.