# Work done to lift a chain

1. Oct 2, 2008

### Default User

1. The problem statement, all variables and given/known data
A chain hangs verticaly from a building. The chain is 30 ft long and is 5 lb/ft3, how much work is needed ot lift the bottom of the chain to the top.

2. Relevant equations
If you put the axis where the chain is hanging your limits would be 0 and -30

3. The attempt at a solution
So I tried $$\int$$$$^{0}_{-30}$$5/30y dy

Then I get 1/12y2 and solve it for 0 and -30 and get 75 lb/ft, but it doesn't seem right.

(sorry if I didnt use the templete right, I'm a noob at this)

2. Oct 2, 2008

### cristo

Staff Emeritus
I'm moving this to physics. Questions based on physics principles whilst still using calculus should be put in the intro physics homework forum.

3. Oct 2, 2008

### Default User

Nobody?

Not even a "no your wrong" or "yes thats right"?