physics Mock by parth

A particle is thrown upwards from ground. It experiences a constant air resistance force which produces a retardation of 2ms^-2 . The ratio of time of ascent to time of descent is: ( g = 10 ms^-2)

• 1:1

• $\sqrt{\frac{2}{3}}$

• $\frac{2}{3}$

• $\sqrt{\frac{3}{2}}$

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 :

•  $\frac{1}{\alpha}$  

•  $\sqrt{\alpha}$  

•  $\frac{1}{\sqrt{\alpha}}$  

•  $\alpha$  

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?

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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  $g=10\ ms^{-2}$  )

• 18 cm

• 14 cm

• 26 cm

• 20 cm

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)

• for  $\mu$   = 0.5 block will be at rest

• for  $\mu$   = 0.2 block will move down

• for  $\mu$   = 0.8 block will move up
  

• Block can never move up for any value of  . $\mu$