$A$ man of weight $W$ is standing on a lift which is moving downward with an acceleration $a$. The apparent weight of the man is

$A$ lift is moving down with an acceleration $a$. $A$ man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are respectively:

$A$ person of mass $50 \, kg$ stands on a weighing scale in a lift. If the lift is descending with a downward acceleration of $9 \, m/s^2$,what would be the reading of the weighing scale (in $, kg$)? (Take $g = 10 \, m/s^2$)

$A$ rough vertical board has an acceleration $a$ so that a $2 \ kg$ block pressing against it does not fall. The coefficient of friction between the block and the board should be

$A$ block of mass $m$ is in contact with the cart $C$ as shown in the figure. The coefficient of static friction between the block and the cart is $\mu$. The acceleration $\alpha$ of the cart that will prevent the block from falling satisfies:

$A$ spring balance and a physical balance are kept in a lift. In these balances,equal masses are placed. If the lift starts moving upwards with constant acceleration,then: