Picking a chain from one end

1. Oct 10, 2008

imranq

1. The problem statement, all variables and given/known data
You have a chain of length 10m with 80kg, how much work does it take to lift this chain from one end to 6ft?

2. Relevant equations

$$\delta = \frac{10}{80} = .125$$

3. The attempt at a solution

$$W = \int{F(x)}\,dx = \int^{6}_{0}{\delta lg}\,dl = \frac{\delta l^2g}{2}$$

I dont think that is right though

2. Oct 10, 2008

Redbelly98

Staff Emeritus
So far so good, you just need to evaluate the integrated expression at the integral's limits.

Is it 6 ft or 6 m?

3. Oct 10, 2008

imranq

Oh whoops! Everything that denotes length is in feet

4. Oct 10, 2008

Redbelly98

Staff Emeritus
Okay. I'm wondering about the "kg" too then.

5. Oct 10, 2008

imranq

I don't really remember the problem so well. But the inherent integral should be the same, no? Unless you refer to lbs as weight or something.

6. Oct 10, 2008

Redbelly98

Staff Emeritus
Yes, the inherent integral is the same. Using lbs can get a little confusing since lbs are a force unit, not mass.