$A$ coin is dropped in a lift. It takes time $t_1$ to reach the floor when the lift is stationary. It takes time $t_2$ when the lift is moving up with constant acceleration. Then:

$A$ lift is moving downwards with an acceleration equal to the acceleration due to gravity. $A$ body of mass $m$ kept on the floor of the lift is pulled horizontally. If the coefficient of friction is $\mu$,then the frictional resistance offered by the body is:

The ratio of the weight of a man in a stationary lift and when it is moving downward with uniform acceleration $a$ is $3 : 2$. The value of $a$ is ($g$ = acceleration due to gravity of the earth).

$A$ rectangular box contains water. It is being pulled to the right with an acceleration $a$. Which of the following options shows the correct shape of the water surface?

$A$ $60\, kg$ man stands on a spring scale in a lift. At some instant,he finds the scale reading has changed from $60\, kg$ to $50\, kg$ for a while and then comes back to the original mark. What should we conclude?

An object of mass $2 \, kg$ is placed at rest in a frame $S_1$ moving with velocity $10 \hat{i} + 5 \hat{j} \, m/s$ and having acceleration $5 \hat{i} + 10 \hat{j} \, m/s^2$. The object is also seen by an observer standing in a frame $S_2$ moving with velocity $5 \hat{i} + 10 \hat{j} \, m/s$. Calculate the net force acting on the object with respect to the $S_2$ frame.