Applications to Physics: work required to lift chain

[paulxzt]

A chain lying on the ground is 10 m long and its mass is 80kg. How much work is required to raise one end of the chain to a height of 6m?

W = F * d

F = mg = (80)(9.8) = 784N

W = integral of (6-x)(784)dx from 0 to 6

can someone help me. am i doing this totally wrong?

 

[skeeter]

linear density, \(\displaystyle \L \lambda = 8 \, kg/m\)

so ... \(\displaystyle \L \frac{dm}{dx} = 8\) and \(\displaystyle \L dm = 8 \, dx\)

work done on an infinitesimal piece of chain ...

\(\displaystyle \L dW = dm \cdot g \cdot (6-x)\)


\(\displaystyle \L dW = g(6-x) \cdot 8 dx\)

\(\displaystyle \L W = 8g \int_0^6 (6-x) dx\)