$A$ 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?

If a trolley accelerates horizontally with acceleration $a$,then the bob is displaced backward from its initial vertical position. The angular deflection of the bob in equilibrium is ..........

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

$A$ person in an elevator accelerating upwards with an acceleration of $2 \, m/s^2$ tosses a coin vertically upwards with a speed of $5 \, m/s$. After how much time will the coin fall back into his hand (in $s$)? $(g = 10 \, m/s^2)$

Cream gets separated out of milk when it is churned,it is due to