$A$ block can slide on a smooth inclined plane of inclination $\theta$ kept on the floor of a lift. When the lift is descending with a retardation $a$,the acceleration of the block relative to the incline is

$A$ wooden wedge of mass $M$ and inclination angle $\alpha$ rests on a smooth floor. $A$ block of mass $m$ is kept on the wedge. $A$ force $F$ is applied on the wedge as shown in the figure such that the block remains stationary with respect to the wedge. The magnitude of the force $F$ is:

$A$ spring balance and a physical balance are kept in a lift. In these balances,equal masses are placed. If the lift starts moving upwards with constant acceleration,then:

$A$ block is kept on a frictionless inclined surface with an angle of inclination '$\alpha$'. The incline is given a horizontal acceleration '$a$' to keep the block stationary relative to the incline. Then '$a$' is equal to:

$A$ person is standing in an elevator. In which of the following situations does he find his weight to be less than his actual weight?

$A$ wedge of height $H$ (fixed) and inclination $\alpha$ (variable) is moving on a smooth horizontal surface with constant acceleration $g \ m/s^2$. $A$ small block is placed at the bottom of the incline as shown in the figure, and it slips on the smooth surface of the incline. Choose the $CORRECT$ statement about the time taken by the block to reach the top of the incline.