Question

If the work required to stretch a spring 1 ft beyond its natural length is 12 ft-lb, how much work is needed to stretch the same spring from its natural length to 3 in? Hint: 1 ft = 12 in

Answer 1

Answer:
`W=(3)/(4) ft-lb`

Step-by-step explanation:

Given

Work required to stretch 1 ft is 12 ft-lb

and we have to find work required to stretch 3 in.

i.e.
`(1)/(4) ft`

`12=(1)/(2)K\left ( 1\right )^2 ------(1)`

`W=(1)/(2)k\left ( (1)/(4)\right )^2-----(2)`

divide (1)&(2)

`(12)/(W)=\left ( (4)/(1)\right )^2`

`W=(12)/(4* 4)`

`W=(3)/(4) ft-lb`