$A$ block is placed between two surfaces as shown in the figure. Find the normal reaction at both surfaces. [Assume $g = 10 \ m/s^2$]

Two equal heavy spheres,each of radius $r$,are in equilibrium within a smooth cup of radius $3r$. The ratio of the reaction between the cup and one sphere to that between the two spheres is:

At the instant $t = 0$,a force $F = kt$ ($k$ is a constant) acts on a small body of mass $m$ resting on a smooth horizontal surface. The force is applied at an angle $\alpha$ with the horizontal. The time at which the body leaves the surface is:

$A$ ladder rests against a frictionless vertical wall,with its upper end $6 \, m$ above the ground and the lower end $4 \, m$ away from the wall. The weight of the ladder is $500 \, N$ and its center of gravity ($C$.$G$.) is at $1/3$ of its length from the lower end. The reaction force from the wall will be (in Newton):

$A$ mass '$M$' is suspended by a rope from a rigid support at point '$P$' as shown in the figure. Another rope is tied at end '$Q$' and pulled horizontally with a force '$F$'. If the rope makes an angle '$\theta$' with the vertical,then the tension in the string '$PQ$' is

$A$ man is standing on a balance and his weight is measured. If he takes a step to the left side,then his weight: