The system of the wedge and the block connected by a massless spring as shown in the figure is released with the spring in its natural length. Friction is absent. Maximum elongation in the spring will be

Options

A. `(3Mg)/(5k)`
B. `(6Mg)/(5k)`
C. `(4Mg)/(5k)`
D. `(8Mg)/(5k)`

Answer

B

Explanation

Using conservation of mechanical energy
`Mg(x_(m)sintheta)=(1)/(2)"K x"_(m)^(2)`
`x_(m)=(2Mgsintheta)/(K)`