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प्रश्न
Explain various types of friction.
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उत्तर
There are two types of Friction:
(1) Static Friction:
Static friction is the force that opposes the initiation of motion of an object on the surface. The magnitude of static frictional force fs lies between
0 ≤ fs ≤ μsN
where, µs – coefficient of static friction
N – Normal force
(2) Kinetic friction:
The frictional force exerted by the surface when an object slides is called kinetic friction. Also called sliding friction or dynamic friction,
fk – µkN
where µk – the coefficient of kinetic friction
N – Normal force exerted by the surface on the object
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संबंधित प्रश्न
State the empirical laws of static and kinetic friction.
Briefly explain ‘rolling friction.'
Briefly explain the origin of friction. Show that in an inclined plane, the angle of friction is equal to the angle of repose.
If a body of mass m is moving on a rough horizontal surface of coefficient of kinetic friction µ, the net resultant force exerted by surface on the body is ______.
A 40 kg wooden crate is being pushed across a wooden floor with a force of 160 N. If µk = 0.3, the acceleration of the crate is ______ m/s2. (g = 10 m/s2}
The minimum radius of a circle along which a cyclist can ride with a velocity 18 km/hr if the coefficient of friction between the tyres and the road is µ = 0.5, is ______ (Take g = 10 m/s2)
The coefficient of static friction between a car's tires and a level road is 0.80. If the car is to be stopped in a maximum time of 3.0 s, its speed cannot exceed.
A block of mass 10 kg starts sliding on a surface with an initial velocity of 9.8 ms-1. The coefficient of friction between the surface and bock is 0.5. The distance covered by the block before coming to rest is ______.
[use g = 9.8 ms-2]
A body starts from rest on a long inclined plane of slope 45°. The coefficient of friction between the body and the plane varies as µ = 0.3 x, where x is distance travelled down the plane. The body will have maximum speed (for g = 10 m/s2) when x = ______.
There are two inclined surfaces of equal length (L) and same angle of inclination 45° with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down, on rough surface than on the smooth surface. The coefficient of kinetic friction (μ) between the object and the rough surface is close to ______.
