A highly rigid cubical block of small mass and side is fixed rigidly on to another…

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A highly rigid cubical block

A

of small mass

M

and side

L

is fixed rigidly on to another cubical block

B

of the same dimensions 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 After the force is withdrawn, block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 (1)

2\pi\sqrt{M\eta L}

(2)

2\pi\sqrt{\frac{M\eta}{L}}

(3)

2\pi\sqrt{\frac{ML}{\eta}}

(4)

2\pi\sqrt{\frac{M}{\eta L}}