1. spring constant

A light spring which has a force constant of 8N/m is cut into two equal parts . What is the force constant for each part ??

isnt that each part has a force constant of 8N/m ??

2. Hi thereddevils

I think it's better to post your question here :
http://www.physicshelpforum.com

And a little hint for you : the answer is no. Now your job is to find out the reason

3. Originally Posted by thereddevils
A light spring which has a force constant of 8N/m is cut into two equal parts . What is the force constant for each part ??

isnt that each part has a force constant of 8N/m ??
$k = 8$ N/m

that means if you apply $8$ N of force, the spring stretches $1$ m

cut the spring in half ... attach them with a light non-stretchable string.

apply a force of 8N. Each piece stretches $0.5$ m

the force in each spring "piece" is 8N

$k_{each \, piece} = \frac{F}{x} = \frac{8}{.5} = 16$ N/m

for two springs in series, the effective force constant of a single spring equivalent to the two is

$k_{eff} = \frac{k_1 \cdot k_2}{k_1 + k_2}$

$k_{eff} = \frac{16 \cdot 16}{16 + 16} = \frac{16^2}{2 \cdot 16} = 8$ N/m