**integral physics application problems** We are now applying calculus to physics problems and I am having trouble coming up with the correct integrals.

An anchor weighing 100 lb in water is attached to a chain weighing 3 lb per foot in water. Find the work done to haul the anchor and chain to the surface of the water from a depth of 25 ft.

I know I need an integral from 0 to 25 but what do I need to multiply my distance term by????

A rectangular swimming pool 50 ft long by 20 ft wide and 10 ft deep is filled with water to a depth of 9 ft. Use an integral to find the work required to pump all the water out over the top.

This one I thought would just be the integral from 0 to 10 of

50 x 20 x 9 x density of water per cubic foot times y dy but I am not getting the correct answer.

Thank you for making this site so helpful and helping not pull all of my hair out!!!!!