1) A force of 2 pounds is required to hold a spring stretched0.2 feet beyond its natural length. How much work (in foot-pounds)is done in stretching the spring from its natural length to 0.9feet beyond its natural length?
2) Work of 3 Joules is done in stretching a spring from itsnatural length to 19 cm beyond its natural length. What is theforce (in Newtons) that holds the spring stretched at the samedistance (19 cm)?
3) How much work is done lifting a 40-pound object from theground to the top of a 30-foot building if the cable used weighs0.5 pounds per foot?
foot-pounds.
