Three sides of a square are formed by bending a rod of length 36 cm. The distance of its CG from an open end is

• 12 cm

• $6\sqrt{2} \mathrm{cm}$

• $8\sqrt{2} \mathrm{cm}$

• None of these

42.

If the resultant of two forces of magnitude P and P$\sqrt{3}$ acting on a particle is of magnitude P, then the angle between them is

• 60°

• 120°

• 90°

• 150°

A particle is dropped from a height 12 g metre and 4 s after anotherparticle is projected from the ground towards it with a velocity 4g ms. The time after which the second particle meets first is

• 4 s

• 2 s

• $\frac{1}{2} \mathrm{s}$

• 1 s

A uniform ladder rests in limiting equilibrium with its lower end on a rough horizontal plane with coefficient of friction µ and its upper end against a smooth vertical wall. If $\mathrm{\theta }$ is the inclination of the ladder with the wall, then $\mathrm{\theta }$ is equal to

• ${\tan }^{-1}\left(\mathrm{u}\right)$

• ${\cot }^{-1}\left(\mathrm{u}\right)$

• ${\cot }^{-1}\left(2\mathrm{u}\right)$

• ${\tan }^{-1}\left(2\mathrm{u}\right)$