posted by Anonymous .
Hooke's law describes a certain light spring of unstressed length 36.0 cm. When one end is attached to the top of a door frame and a 6.40 kg object is hung from the other end, the length of the spring is 44.00 cm.
(a) Find its spring constant
I found the correct answer to be k=784 N/m
(b) The load and the spring are taken down. Two people pull in opposite directions on the ends of the spring, each with a force of 170 N. Find the length of the spring in this situation.
I thought the answer was 0.7937m but this is incorrect. I have no other idea on how to solve for part b.
The length of the spring under tension is the amount of stretching PLUS the original unstressed length.
The stretch amount is F/k = 170/784
= 0.217 m = 21.7 cm
Add 36.0 cm to that.