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 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 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 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
To avoid slipping while walking on ice one should take smallest steps because of the
larger friction
larger normal reaction
smaller friction
smaller normal reaction
Which of the following is the dimension of coefficient of friction?
[MLT-2]
[M0L0T0]
[M2LT-2]
[M2LT]
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
A car turns a corner on a slippery road at a constant speed of 12 m/s. If the coefficient of friction is 0.4, the minimum radius of the arc in metre in which the car turns is
72
36
18
9
A disc revolves in a horizontal plane at a steady rate of 3 r.p.s.A coin will remain on the disc if it is kept at a distance of 2 cm from the axis of rotation.What is the coeffecient of friction between the coin and the disc? g = 9.8 m/s2
0.724
0.856
0.987
0.685
Consider a car moving along a straight horizontal road with a speed of 72 km/hr.If the coeffecient of static friction between the tyres and the road is 0.5,the shortest distance in which the car can be stopped is
(Take g = 10 m/s2)
30 m
40 m
72 m
20 m
