A particle starts moving with a constant angular acceleration $\alpha$ in a circular path. The time at which the magnitudes of tangential and radial acceleration are equal is :

A body is at rest at x = 0. At t = 0, it starts moving in the positive x-direction with a constant acceleration. At the same instant another body passes through x = 0 moving in the positive x-direction with a constant speed. The position of the first body is given by x₁(t) after time t and that of the second body by x₂(t) after the same time interval. Which of the following graphs correctly describes(x₁-x₂) as a function of time t?

A plane is inclined at an angle  $\alpha=30\degree$   with respect to the horizontal. A particle is projected with a speed  $u=2\ ms^{-1}$  from the base of the plane, making an angle $\theta=15\degree$   with respect to the plane as shown in the figure. The distance from the base, at which the particle hits the plane is close to: ( Take  $g=10\ ms^{-2}$  )

A block of mass 4 kg is acted upon by a 50 N force as shown. The friction coefficient between block and wall is $\mu$  ( MORE THAN ONE CORRECT)