Two trolleys $A$ and $B$ are moving with accelerations $a$ and $2a$ respectively in the same direction. To an observer in trolley $A$,the magnitude of the pseudo force acting on a block of mass $m$ on trolley $B$ is

If the rope of a lift breaks suddenly,what is the tension exerted by the floor of the lift on a person inside? ($a =$ acceleration of the lift)

Find the apparent weight of a body of mass $1.0 \,kg$ falling with an acceleration of $10 \,ms^{-2}$. $\left(g \approx 10 \,ms^{-2}\right)$

$A$ block of mass $m$ is kept on a wedge of mass $M$,as shown in the figure,such that mass $m$ remains stationary with respect to the wedge. The magnitude of force $P$ is

$A$ very broad elevator is going up vertically with a constant acceleration of $2\,m/s^2$. At the instant when its velocity is $4\,m/s$,a ball is projected from the floor of the lift with a speed of $4\,m/s$ relative to the floor at an elevation of $30^{\circ}$. The time taken by the ball to return to the floor is $..............\,s$ $(g=10\,m/s^2)$.

$A$ boy whose mass is $50\,kg$ stands on a spring balance inside a lift. The lift starts to ascend with an acceleration of $2\,m/s^2$. The reading of the machine or balance $(g = 10\,m/s^2)$ is ........ $kg$.