In an elevator moving vertically up with an acceleration $g$,the force exerted on the floor by a passenger of mass $M$ is

$A$ truck is stationary and has a bob suspended by a light string in a frame attached to the truck. The truck suddenly moves to the right with an acceleration of $a$. The pendulum will tilt:

$A$ boy having a mass equal to $40 \, kg$ is standing in an elevator. The force felt by the feet of the boy (apparent weight) will be greatest when the elevator $(g = 9.8 \, m/s^2)$:

$A$ 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 $s$)? $(g = 10 \, m/s^2)$

$A$ 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:

$A$ rocket is moving in a gravity-free space with a constant acceleration of $2 \ ms^{-2}$ along the $+x$ direction (see figure). The length of a chamber inside the rocket is $4 \ m$. $A$ ball is thrown from the left end of the chamber in the $+x$ direction with a speed of $0.3 \ ms^{-1}$ relative to the rocket. At the same time,another ball is thrown in the $-x$ direction with a speed of $0.2 \ ms^{-1}$ from its right end relative to the rocket. The time in seconds when the two balls hit each other is: