Two masses $M_1$ and $M_2$ are attached to the ends of a string which passes over a pulley attached to the top of a double inclined plane of angles of inclination $\alpha$ and $\beta$. If the system is released,the acceleration $a$ of the system is given by:

$A$ smooth inclined plane is inclined at an angle $\theta$ with the horizontal. $A$ body starts from rest and slides down the inclined surface. The time taken by it to reach the bottom is

$A$ body of mass $1\, kg$ lies on a smooth inclined plane. The body is subjected to a horizontal force $F = 10\, N$ as shown in the figure. The magnitude of the net normal reaction on the body is:

$A$ body is slipping from an inclined plane of height $h$ and length $l$. If the angle of inclination is $\theta$,the time taken by the body to come from the top to the bottom of this inclined plane is

$A$ solid sphere,a hollow sphere,and a ring are released from the top of a frictionless inclined plane,causing them to slide down the plane. For which object is the acceleration down the plane the maximum?

$A$ football of radius $R$ is kept on a hole of radius $r$ (where the diameter of the hole is $2r$ and $r < R$) made on a plank kept horizontally. One end of the plank is now lifted so that it gets tilted,making an angle $\theta$ with the horizontal as shown in the figure. The maximum value of $\theta$ such that the football does not start rolling down the plank satisfies (figure is schematic and not drawn to scale) -