List of top Physics Questions on laws of motion asked in Delhi UMET/DPMT

A body of mass $M$ starts sliding down on the inclined plane where the critical angle is $\angle ACB = 30^{\circ}$ as shown in figure. The coefficient of kinetic friction will be

Angle of repose is equal to the angle of limiting friction. When the body is just at the point of motion, the force of friction in this stage is called limiting friction.

Consider a vehicle going on a horizontal road towards east. Neglect any force by the air. The frictional force on the vehicle by the road

A body takes time $t$ to reach the bottom of an inclined plane of angle $ \theta $ with the horizontal. If the plane is made rough, time taken now is $2t$. The coefficient of friction of the rough surface is: