A projectile is launched with 200kg m/s of momentum and 1000 J of kinetic energy. What is the mass of the projectile.

The answer is said to be 20 kg but I can't get it. I tried this but it didn't work:

p=mv=200 m=200/v
I plugged that into this equation:
KE=1/2mv^2=1000 = 1/2(200/v)v^2=1000

Can anyone help? THanks

1 answer

Nevermind, I got it.

I was solving for velocity the first time when it should have been mass.