Calculating Work to Stretch a Spring from 30cm to 41cm

[Minihoudini]

Homework Statement

A spring has a natural length of 30 cm. If a 21 N force is required to keep it stretched to a length of 35 cm, how much work W is required to stretch it from 30 cm to 41 cm? (Round your answer to the nearest hundredth.)

Homework Equations

41cm-30cm=11cm so its .11m
21n=.35mk k= 21/.35 k=60 so f(x)= 0 to .11 of 60x so the integration is 30x^2 |0 to .11

so it should be 30(.11)^2 = 363/1000

The Attempt at a Solution

 

[HallsofIvy]

What is your question?

Yes, what you have doneis correct. Since you are told to "Round your answer to the nearest hundredth." your answer should be 0.36 Joules. (Don't forget the units, "Joules"- that's an important part of the answer.