Answer
$125\text{ lb}\cdot\text{ft}$
Work Step by Step
The weight is uniformly distributed along the chain.
$F= \frac{25\text{ lb}}{10\text{ ft}} = 2.5\text{ lb/ft}$
We’ll integrate over the chain’s length to add up the work.
$W =\int_0^{10} 2.5x dx=2.5\int_0^{10}x dx$
$=2.5\left[\frac{x^2}{2}\right]_0^{10}=125$
