[ Homework Help ] Open Question : College Physical Science Problem?

Submitted by HowU on Tue, 02/09/2010 - 00:00

The work done in lifting 30kg of bricks to a height of 20m is
a. 61J
b.600J
c.2940J
d.5880J

Can you explain hoe you got the answer?
I'm so confused... :(