A block of mass 10 kg is placed on a rough horizontal surface whose coeffecient of friction is 0.5.If a horizontal force of 100 N is applied on it,then acceleration of block will be :

If the normal force is doubled,then coefficient of friction is

The upper half of an inclined plane of inclination θ is perfectly smooth while the lower is rough.A body starting from rest at the top comes back to rest at the bottom,if the coeffecient of friction for the lower half is given by

A smooth block is released at rest on a 45⁰ incline and then slides a distance d. The time taken to slide is n times as much to slide on rough incline than on a smooth incline. The coefficient of friction is

Which of the following is the dimension of coefficient of friction?

Assertion (A): Frictional forces are conservative forces.

Reason(R): Potential energy can be associated with frictional forces.

A block of metal of mass 2 kg is resting on a frictionless floor.It is struck by a jet releasing water at the rate of 1 kg/sec and at a speed of 5 m/s.What will be the initial acceleration of the block ?

A block is kept on a frictionless inclined surface with angle of inclination α. The incline is given an acceleration a to keep the block stationary. Then a is equal to

A block of mass 50 kg is placed on a rough inclined plane.The inclination is gradually increased to 30° when the block starts sliding down.Find the magnitude of the limiting friction.

A block of mass m is on an inclined plane of angle θ. The coefficient of friction between the block and the plane is μ and tanθ>μ. The block is held stationary by applying a force P parallel to the plane. The direction of force pointing up the plane is taken to be positive. As P is varied from P₁ = mg(sinθ-μcosθ) to P₂ = mg(sinθ+μcosθ), the frictional force f versus P graph will look like