$A$ block of mass $M$ is at rest on a plane surface inclined at an angle $\theta$ to the horizontal. The magnitude of the force exerted by the plane on the block is

$A$ car is moving on a plane inclined at $30^{\circ}$ to the horizontal with an acceleration of $10 \, ms^{-2}$ parallel to the plane upward. $A$ bob is suspended by a string from the roof of the car. The angle in degrees which the string makes with the vertical is ...... . (Take $g = 10 \, ms^{-2}$)

$A$ body starts falling freely from height $H$ and hits an inclined plane in its path at height $h$ from the ground. As a result of this perfectly elastic impact,the direction of the velocity of the body becomes horizontal. The value of $\frac{H}{h}$ for which the body will take the maximum time to reach the ground is . . . . . . .

$A$ solid sphere,a hollow sphere,and a ring are released from the top of a frictionless inclined plane. They slide down the plane. Which object will have the maximum linear acceleration at the bottom of the plane? The objects do not roll on the plane.

$A$ body of mass $5\,kg$ is suspended by a spring balance on an inclined plane as shown in the figure. The spring balance measures ............ $N$.

$A$ block of mass $200\, g$ is kept stationary on a smooth inclined plane by applying a minimum horizontal force $F = \sqrt{x}\, N$ as shown in the figure. The value of $x = .....$