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 ?
3.5 m/s2
4.5 m/s2
2.5 m/s2
none of these
A heavy uniform chain lies on horizontal table top.If the coeffecient of friction between the chain and the table surface is 0.25,then the maximum friction of the length of the chain that can hang over one edge of the table is
20 %
25 %
35 %
15 %
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
When two surfaces are coated with lubricant,then they
stick to each other
slide upon each other
roll upon each other
A drum of radius R and mass M ,rolls down without slipping along an inclined plane of angle θ.The frictional force
converts translational energy to rotational energy
dissipates energy as heat
decreases the rotational motion
decreases the rotational and translational motion
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 :
10 m/s2
5 m/s2
15 m/s2
0.5 m/s2
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
A block is lying static on the floor.The maximum value of static frictional force on the block is 10 N.If a horizontal force of 8 N is applied to the block,what will be the frictional force on the block ?
2 N
18 N
8 N
10 N
The maximum velocity (in ms-1) with which a car driver must traverse a flat curve of radius 150 m and coefficient of friction 0.6 to avoid skidding is
60
30
15
25
A block of 10 kg is pulled at a constant speed on a rough horizontal surface by a force of 20 N.Find the co- effecient of kinetic friction .Given that g = 10 m/s2 .
0.2
0.5
0.85
0.7
