The work done to "HOLD" a load of bricks at any height is zero.
Work is done only when force acts through a DISTANCE.
The work done to LIFT 30 kg of anything to 20m higher than
it already is, is
(force) · (vertical distance)
= (mass) · (gravity) · (vertical distance)
= (30 kg) · (9.8 m/s²) · (20 m)
= 5,880 joules
