$A$ 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 $g = 10 \, ms^{-2}$)

For the given system,the acceleration of the system is ........... $ms^{-2}$ $(\sin 37^\circ = 0.60, \sin 53^\circ = 0.80)$.

Describe Galileo's experiment of an inclined plane regarding motion.

$A$ body sliding on a smooth inclined plane requires $4$ seconds to reach the bottom starting from rest at the top. How much time does it take to cover one-fourth distance starting from rest at the top?

$A$ double inclined plane as shown in the figure has a fixed horizontal base and smooth faces with the same angle of inclination of $30^{\circ}$. $A$ block of mass $m_2 = 300 \ g$ is on one face and is connected by a cord passing over a frictionless pulley to a second block of mass $m_1 = 200 \ g$ kept on the other face. The acceleration with which the system of the blocks moves is ........ $\%$ of acceleration due to gravity $(g)$.

The horizontal acceleration that should be given to a smooth inclined plane of angle $\sin^{-1} (1/l)$ to keep an object stationary on the plane relative to the inclined plane is