$A$ cork is submerged in water by a spring attached to the bottom of a bowl. When the bowl is kept in an elevator moving with an acceleration $a$ downwards, the length of the spring:

$A$ 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 ........... $N$ $(g = 9.8 \, m/s^2)$.

$A$ car is moving with a uniform speed on a level road. Inside the car,there is a balloon filled with helium and attached to a piece of string tied to the floor. The string is observed to be vertical. The car now takes a left turn while maintaining the same speed on the level road. The balloon in the car will:

$A$ person in an elevator accelerating upwards with an acceleration of $2\,ms^{-2}$,tosses a coin vertically upwards with a speed of $20\,ms^{-1}$. After how much time will the coin fall back into his hand? (Take $g = 10\,ms^{-2}$)

$A$ body of mass $2\, kg$ is hung on a spring balance mounted vertically in a lift. If the lift moves up with an acceleration equal to the acceleration due to gravity $g$,the reading on the spring balance will be .......... $kg$.

The weight of a man in a lift moving in an upward direction with an acceleration '$a$' is $660 \text{ N}$. When the lift moves in the downward direction with the same acceleration, his weight is found to be $380 \text{ N}$. The real weight of the man when the lift is at rest is: (in $\text{ N}$)