Two equal masses are attached to the two end of a spring of force constant `k` the masses are pulled out symmetrically to stretch the spring by a length `2x_(0)` over its natural length. Find the work done by the spring on each mass.

Options

A. `kx_(0)^(2)`
B. `-(1)/(2)kx_(0)^(2)`
C. `2kx_(0)^(2)`
D. `-kx_(0)^(2)`

Answer

C

Explanation

Point B, D and E are symmetrically spaced with respect to the entry point A. Hence B,D,E have a common potential. Similarly points H,F and C are symmetrically spaced with respect to exit point G. Hence H,F,C have a common potential. Equivalent circuit as shown above.
`R_("eff")=(R )/(3)+(R )/(6)+(R )/(3)=(5R)/(6)`