Find equivalent spring constant for the system:

Options

A. K
B. 2 K
C. 64 K
D. 8 K

Answer

C

Explanation

If block moves by x then elongation in spring
`=8x=T/(8K)` …(i)

If we replace by equivalent system
`:. T/x=K'` …(ii)
where K' is equivalent spring constant from Eqs (i) and (ii)
`T/x = 64 K=K'`
`:. K'=64K`