Q. A block resting on the horizontal surface executes ... in horizontal plane with amplitude ‘’. The frequency of oscillation for which the block just starts to slip is ( coefficient of friction, gravitational acceleration)

 2170  217 MHT CETMHT CET 2014 Report Error

Solution:

When restoring force will become equal to the frictional force, block will start to slip.
Restoring force Friction force

Now, frequency
From Eq. (i),