A rubber band (two parallel strands of elastic material) has a force constant of 1 N/m. If the bank is cut in one place such that it now forms a "sin"gle long strand of elastic material, then the new spring constant will be

Options

A. 5 N/m
B. 0.5 N/m
C. 0.25 N/m
D. 2 N/m

Answer

C

Explanation

Initially strands are in parallel.
`therefore` Their force constant `=2K= 1N//m therefore K=0.5 N//m`
When one cut is taken in the rubber loop, we get two pieces joined in series.
`therefore` The force constant will be `K'=(K)/(2)=(0.5)/(2)`
`therefore K'=0.25 N//m`