A highly rigid cubical block (A) of small mass (M) and slide (L) is fixed rigidly on to another cubical block (B) of the same dimesions and of low modulus of rigidity (eta) such that the lower face of (A) completely covers the upper face of (B). The lower face of (B) is rigidly held on a horizontal surface. (A) small force (F) is applied perpendicular to one of the sides faces of (A). After the force is withdrawn, block (A) executes small oscillations the time period of which is given by.

Options

A. `2pi sqrt(M etaL)`
B. `2pi sqrt(Meta//L)`
C. `2pi sqrt(ML//eta)`
D. `2pi sqrt(M//etaL)`

Answer

D

Explanation

`[eta]=[ML^(-1)T^(-2)]`
Hence, `[sqrt((M)/(etaL))]=sqrt(([M])/([ML^(-1)T^(-2)][L]))=[T]`