Laws of Motion Questions (MCQs), NEET, JEE Main – Test 04 1

To determine the coefficient of friction between a rough surface and a block, the surface is kept inclined at 45° and the block is released from rest. The block takes a time t in moving a distance d. The rough surface is then replaced by a smooth surface and the same experiment is repeated. The block now takes a time t/2 in moving down the same distance d. The coefficient of friction is [WB JEEM 2014]

A block is pushed momentarily on a horizontal surface with initial velocity ‘v’. If ‘μ’ is the coefficient of sliding friction between the block and surface, the block will come to rest after time (‘g’ = acceleration due to gravity) [MH-CET 2014]

The upper half of an inclined plane of inclination θ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by [NEET UG 2013]

The minimum force required to start pushing a body up a rough (frictional coefficient μ) inclined plane is F₁ while the minimum force needed to prevent it from sliding down is F₂. If the inclined plane makes an angle θ from the horizontal such that tan θ = 2μ, then the ratio F₁/F₂  is [AIEEE 2011]

The figure shows the position–time (x–t) graph of one-dimensional motion of a body of mass 0.4 kg. The magnitude of each impulse is [AIEEE 2010]