$A$ man weighing $75 \,kg$ is standing in a lift. The weight of the man standing on a weighing machine kept in the lift when the lift is moving downwards freely under gravity is

In a $U$-tube,the liquid level stands at the same level when it is at rest. When the $U$-tube is accelerated towards the right with acceleration $a$,as shown in the figure,the difference $h$ between the levels of the two arms is:

$A$ man weighs $80\,kg.$ He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of $5\,m/s^2.$ What would be the reading on the scale? $(g = 10\,m/s^2)$ ............ $N$

$A$ point mass $m$ is suspended from a light thread of length $l$,fixed at $O$,and is whirled in a horizontal circle at a constant speed as shown. From your point of view,stationary with respect to the mass,the forces on the mass are

An elevator is moving vertically up with an acceleration $a$. The force exerted on the floor by a passenger of mass $m$ is:

$A$ ball is suspended on a thread from the ceiling of a car. The brakes are applied and the speed of the car changes from $5\, m/s$ to $\frac{5}{3}\, m/s$ during the time interval of $3\, s$. The angle that the thread will deviate from the vertical in the new equilibrium position is: