Advertisements
Advertisements
प्रश्न
State the empirical laws of static and kinetic friction.
Advertisements
उत्तर
The empirical laws of friction are:
- Friction is independent of the surface of contact.
- The coefficient of kinetic friction is less than the coefficient of static friction.
- The direction of frictional force is always opposite to the motion of one body over the other.
- Frictional force always acts on the object parallel to the surface on which the object is placed,
- The magnitude of frictional force between any two bodies in contact is directly proportional to the normal reaction between them.
APPEARS IN
संबंधित प्रश्न
An object of mass m begins to move on the plane inclined at an angle θ. The coefficient of static friction of inclined surfaces is µs. The maximum static friction experienced by the mass is ______
Explain various types of friction.
Suggest a few methods to reduce friction.
A long stick rests on the surface. A person standing 10 m away from the stick. With what minimum speed an object of mass 0.5 kg should he has thrown so that it hits the stick. (Assume the coefficient of kinetic friction is 0.7).
Briefly explain the origin of friction. Show that in an inclined plane, the angle of friction is equal to the angle of repose.
A block of mass 20 kg is sliding on a surface is inclined at an angle of 45° with the horizontal. What will be the acceleration of the block if the coefficient of kinetic friction between the block and the surface is 0.7?
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}
A chain of mass 'M' and length 'L' is put on a rough horizontal surface and is pulled by constant horizontal force 'F' as shown in the figure. The velocity of the chain as it turns completely ______.
(Coefficient of friction = μ)
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 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 = ______.
