If the net force on a system is zero,then:

Two fixed frictionless inclined planes making an angle $30^\circ$ and $60^\circ$ with the vertical are shown in the figure. Two blocks $A$ and $B$ are placed on the two planes. What is the relative vertical acceleration of $A$ with respect to $B$?

The mass of a hydrogen molecule is $3.32 \times 10^{-27} \ kg$. If $10^{23}$ hydrogen molecules strike,per second,a fixed wall of area $2 \ cm^2$ at an angle of $45^\circ$ to the normal,and rebound elastically with a speed of $10^3 \ m/s$,then the pressure on the wall is nearly:

An object of mass $m$ is being moved with a constant velocity under the action of an applied force of $2\, N$ along a frictionless surface with the following surface profile. The correct applied force vs distance graph will be:

Consider the following statements $A$ and $B$ and identify the correct answer given below:
$(A)$ $A$ body initially at rest is acted upon by a constant force. The rate of change of its kinetic energy varies linearly with time.
$(B)$ When a body is at rest,it must be in equilibrium.

$A$ $20 \text{ ton}$ truck is travelling along a curved path of radius $240 \text{ m}$. If the center of gravity of the truck above the ground is $2 \text{ m}$ and the distance between its wheels is $1.5 \text{ m}$, the maximum speed of the truck with which it can travel without toppling over is (Acceleration due to gravity $= 10 \text{ ms}^{-2}$) (in $\text{ ms}^{-1}$)