You may choose more than one answer: A. It is directly proportional to the size of the area of contact between two surfaces.
B. It is influenced by the roughness of the surfaces in contact
C. It is dependant upon the mass of a sliding body on an inclined plane moving under the influence of gravity
D. It is defined by the ratio of the frictional force to the normal force
this is a question from my work!!
B. It is influenced by the roughness of the surfaces in contact
C. It is dependant upon the mass of a sliding body on an inclined plane moving under the influence of gravity
D. It is defined by the ratio of the frictional force to the normal force
this is a question from my work!!
-
since f=uN then u=f/N so D is correct. Also since N is just the normal force which is dependent on mass C is correct to. And the more rough the surface the higher the coefficient of friction. For example Ice has a low coefficient as opposed to concrete.
The coefficient of Friction is the same no matter how wide of an object you drag on the surface so A is not true.
Final answer B,C &D.
The coefficient of Friction is the same no matter how wide of an object you drag on the surface so A is not true.
Final answer B,C &D.
-
well there are few laws of friction. so hope this should help you.
Amontons' First Law: The force of friction is directly proportional to the applied load.
Amontons' Second Law: The force of friction is independent of the apparent area of contact.
Coulomb's Law of Friction: Kinetic friction is independent of the sliding velocity.
Dry surfaces
For low surface pressures the friction is directly proportional to the pressure between the surfaces. As the pressure rises the friction factor rises slightly. At very high pressure the friction factor then quickly increases to seizing
For low surface pressures the coefficient of friction is independent of surface area.
At low velocities the friction is independent of the relative surface velocity. At higher velocities the coefficent of friction decreases.
Well lubricated surfaces
The friction resistance is almost independent of the specific pressure between the surfaces.
At low pressures the friction varies directly as the relative surface speed
At high pressures the friction is high at low velocities falling as the velocity increases to a minimum at about 0,6m/s. The friction then rises in proportion the velocity 2.
The friction is not so dependent of the surface materials
The friction is related to the temperature which affects the viscosity of the lubricant.
for static friction
μ = F /N
For a horizontal surface the horizontal force (F) to move a solid resting on a flat surface
F= μ x mass of solid x g.
Amontons' First Law: The force of friction is directly proportional to the applied load.
Amontons' Second Law: The force of friction is independent of the apparent area of contact.
Coulomb's Law of Friction: Kinetic friction is independent of the sliding velocity.
Dry surfaces
For low surface pressures the friction is directly proportional to the pressure between the surfaces. As the pressure rises the friction factor rises slightly. At very high pressure the friction factor then quickly increases to seizing
For low surface pressures the coefficient of friction is independent of surface area.
At low velocities the friction is independent of the relative surface velocity. At higher velocities the coefficent of friction decreases.
Well lubricated surfaces
The friction resistance is almost independent of the specific pressure between the surfaces.
At low pressures the friction varies directly as the relative surface speed
At high pressures the friction is high at low velocities falling as the velocity increases to a minimum at about 0,6m/s. The friction then rises in proportion the velocity 2.
The friction is not so dependent of the surface materials
The friction is related to the temperature which affects the viscosity of the lubricant.
for static friction
μ = F /N
For a horizontal surface the horizontal force (F) to move a solid resting on a flat surface
F= μ x mass of solid x g.