Question

a force of 4lbs is required to hold a spring stretched 0.6 ft beyond its natural length. how much work (ft-lb) is done stretching the spring from its natural length to 1.1 ft beyond its natural length?

Answer 1

do you know Hook's Law?

Answer 2

got it!:) 4.0315

Answer 3

Force = K * X
where X is distance and K is the spring constant
you can use F= 4 lbs when X= 0.6 ft to find K
then find F when X = 1.1

work done will be F * X or F*1.1 or K*1.1^2