A marble block of mass 2 kg lying on ice, when given a velocity of 6 ms-1, is stopped by friction in 10 s. Then the coefficient of friction is
0.02
0.03
0.06
0.01
Two iron blocks of equal mass but with double surface area slide down an inclined plane with friction coefficient μ.If the first block with surface area A experience a frictional force f, then the second block with surface area 2A will experience a frictional force
f/2
f
2f
4f
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
Friction is the result of
gravitational acceleration
molecular interaction
magnetic interaction
nuclear interaction
If the normal force is doubled,then coefficient of friction is
halved
tripled
doubled
not changed
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
A block of mass 2 kg rests on a rough inclined plane making an angle 300 with the horizontal. The coefficient of static friction between the block and the plane is 0.7. The frictional force on the block is
9.8 N
0.7×9.8 N
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
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
18N
8N
10N
The upper half of an inclined plane with inclination θ is perfectly smooth, while the lower half is rough. A body starting from rest at the top will again come to rest at the bottom, if the coefficient of friction for the lower half is given by
2 tanθ
tanθ
2 sinθ
2 cosθ