# Math Help - Rectangular tank with a base 3 feet by 4 feet.. How much work?

1. ## Rectangular tank with a base 3 feet by 4 feet.. How much work?

A rectangular tank with a base 3 feet by 4 feet and a height of 2 feet is full of oil. The oil weights 58.8 pounds per cubic foot. How much work is done in pumping water out of the top edge in order to empty the tank?
Answer came out to be 1410.
3X4 delta y 58.8(12)delta(y) distance (2-y) integrating at (0) and (2) => 705(2-y)dy = 1410 is this correct?

2. Originally Posted by xterminal01
A rectangular tank with a base 3 feet by 4 feet and a height of 2 feet is full of oil. The oil weights 58.8 pounds per cubic foot. How much work is done in pumping water out of the top edge in order to empty the tank?
Answer came out to be 1410.
3X4 delta y 58.8(12)delta(y) distance (2-y) integrating at (0) and (2) => 705(2-y)dy = 1410 is this correct?
work done is the same as lifting the tank's center of mass 1 ft ...

$24 \cdot 58.8 \cdot 1 = 1411.2$ ft-lbs

3. I am in a calculus class, if i write that on the test i'll get a zero...