Calculating Work on a Compressed Spring

[kari82]

I'm not able to get any of the multiple choice answers. Please help.

a force of 1100 lb compresses a spring from its natural length of 17in to a length of 14in. How much work is done in compressing it from 14in to 9in?

a)4600
b)0.075
c)10000
d)20000

What i did was F(x)=kx => 1100=3k => k=366.7

W=∫366.7x dx from x=3 to x=8, which equals 10084.25

is this answer correct?

 

[Mark44]

I get 10,083.3 (in-lb), which is close to what you got. My answer differs from yours because I didn't round 1100/3.

The answer closest to this is c, for what it's worth.

 

[kari82]

thanks!