In the figure shown,$P$ is a plate on which a wedge $B$ is placed,and on $B$ a block $A$ of mass $m$ is placed. The plate is suddenly removed and the system of $B$ and $A$ is allowed to fall under gravity. Neglecting any force due to air on $A$ and $B$,the normal force on $A$ due to $B$ is

$A$ person of $60 \,kg$ mass is in a lift which is coming down such that the man exerts a force of $150 \,N$ on the floor of the lift. Then the acceleration of the lift is $\left(g=10 \,ms^{-2}\right)$ (in $\,ms^{-2}$)

$A$ piece of wire is bent in the shape of a parabola $y=kx^2$ ($y$-axis vertical) with a bead of mass $m$ on it. The bead can slide on the wire without friction. It stays at the lowest point of the parabola when the wire is at rest. The wire is now accelerated parallel to the $x$-axis with a constant acceleration $a$. The distance of the new equilibrium position of the bead,where the bead can stay at rest with respect to the wire,from the $y$-axis is

Why do we feel dizzy when riding a giant wheel (Ferris wheel) rotating in a vertical plane?

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 $\text{ N}$)

$A$ 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: