A spring of force constant k is cut into lengths of ratio 1:2:3. They are connected in series and the new force constant is k'. Then they are connected in parallel and force constant is k''. Then k':k'' is:
1:9
1:14
1:6
1:11
Solution:
spring in series 1/k' = 1/k + 1/2k + 1/3k → k' = 6k/11