A bullet flying at a speed of 800 m / s at a height of 1.5 m has a kinetic energy of 2880 J. Determine the mass

A bullet flying at a speed of 800 m / s at a height of 1.5 m has a kinetic energy of 2880 J. Determine the mass of the bullet and the total mechanical energy.

given:
v = 800m / s
h = 1.5m
Ek = 2880J
m =?
E =?
decision:
Ek = mv ^ 2/2 = 2880
mv ^ 2 = 5760
m = 5760/800 ^ 2 = 0.009 kg
Ep = mgh = 0.009 × 10 × 1.5 = 0.135 J
E = Ek + Ep = 2880 + 0.15 = 2880.135 J