Very basic but i don't understand it...

Answer is 392J and i get 392000J.A particle of mass 2kg falls freely from rest. Calculate kinetic energy when it has descended 20 meters.

But i just did 2000(weight) x 9.8(gravity) x 20(distance)

And i think thats wrong...well it must be because the answer i have is wrong lol.

Any help please?