The readings shown in two extended spring balances,$S_1$ and $S_2$,are $60\,kg$ and $30\,kg$ respectively. The lift is accelerating upward with an acceleration of $10\,m/s^2$. The mass $m$ is stationary with respect to the lift. Then the mass of the block will be ......... $kg$. (Take $g = 10\,m/s^2$)

The spring balance inside a lift suspends an object. As the lift begins to ascend,the reading indicated by the spring balance will

$A$ 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

$A$ stunt man jumps his car over a crater as shown (neglect air resistance).

$A$ boy of $50 \, kg$ is in a lift moving down with an acceleration of $9.8 \, m/s^2$. The apparent weight of the boy is ........... $N$ $(g = 9.8 \, m/s^2)$.

Inside a horizontally moving box,an experimenter finds that when an object is placed on a smooth horizontal table and is released,it moves with an acceleration of $10\,m/s^2$. In this box,if a $1\,kg$ body is suspended with a light string,the tension in the string in the equilibrium position (with respect to the experimenter) will be $.........\,N$. (Take $g = 10\,m/s^2$)