Answer Happy

If a force of 90 lbs stretches a 120-inch spring by 12 inches, find the work (in lb.ft) done in stretching the spring from 144 inches to 168 inches. . (1 Point) 240 lb.ft 460 lb.ft 100 lb.ft 540 lb.ft 270 lb.ft 380 lb.ft
A cable weighing 3.0 lb/ft and 50 ft long is hanging from a crane with a weight of 800 lbs at its end. Find the work (in lb.ft) done in drawing up the weight to the crane. (1 Point) 35470 lb.ft 227500 lb.ft 3750 lb.ft 110550 lb.ft 47500 lb.ft 55680 lb.ft O 43750 lb.ft