Find the force $F$ required on the cart so that the $2 \ kg$ and $1 \ kg$ blocks remain stationary relative to the cart.

The apparent weight of a girl of mass $30 \ kg$ when she is in a lift moving vertically upwards with an acceleration of $2 \ m \ s^{-2}$ is (Acceleration due to gravity $= 10 \ m \ s^{-2}$) (in $N$)

$A$ body is thrown up in a lift with a velocity $u$ relative to the lift,and the time of flight is found to be $t$. The acceleration with which the lift is moving up is:

Two bodies of masses $m_1$ and $m_2$ are connected by a light string which passes over a frictionless,massless pulley. If the pulley is moving upward with uniform acceleration $\frac{g}{2}$,then the tension in the string will be .........

$A$ plumb bob is hanging from the ceiling of a car. If the car moves with an acceleration $a$,the angle made by the string with the vertical is

$A$ man of weight $W$ is standing on a lift which is moving downward with an acceleration $a$. The apparent weight of the man is