An 8 foot chain weighs 120 pounds. A large robot is holding one end of the chain 3 feet
above the ground, so that 5 feet of the chain are on the ground. How much work must the robot do to
lift this end of the chain from a height of 3 feet to a height of 10 feet?

work = force x distance

distance is (10-y)

work = 120 [integral [3,10] (10-y)dy]