PPT: Friction | Engineering Mechanics - Civil Engineering (CE) PDF Download

 Page 1


• Friction is a force between two surfaces that are
sliding, or trying to slide across one another, for
example when you try to push a toy car along the
floor.
• Friction always works in the direction opposite from
the direction of the motion of the object. It always
parallel to the plane of contact.
Moving
Friction
Friction
Page 2


• Friction is a force between two surfaces that are
sliding, or trying to slide across one another, for
example when you try to push a toy car along the
floor.
• Friction always works in the direction opposite from
the direction of the motion of the object. It always
parallel to the plane of contact.
Moving
Friction
Friction
• The Major Cause of the friction is the interlocking of
minute projections on the surfaces which opposes the
relative motion.
Reason for Friction
The amount of friction depends on the materials from 
which the two surfaces are made. The rougher the surface, 
the more friction is produced
Page 3


• Friction is a force between two surfaces that are
sliding, or trying to slide across one another, for
example when you try to push a toy car along the
floor.
• Friction always works in the direction opposite from
the direction of the motion of the object. It always
parallel to the plane of contact.
Moving
Friction
Friction
• The Major Cause of the friction is the interlocking of
minute projections on the surfaces which opposes the
relative motion.
Reason for Friction
The amount of friction depends on the materials from 
which the two surfaces are made. The rougher the surface, 
the more friction is produced
Types of Friction
Page 4


• Friction is a force between two surfaces that are
sliding, or trying to slide across one another, for
example when you try to push a toy car along the
floor.
• Friction always works in the direction opposite from
the direction of the motion of the object. It always
parallel to the plane of contact.
Moving
Friction
Friction
• The Major Cause of the friction is the interlocking of
minute projections on the surfaces which opposes the
relative motion.
Reason for Friction
The amount of friction depends on the materials from 
which the two surfaces are made. The rougher the surface, 
the more friction is produced
Types of Friction
FRICTION
?The Resistance offered by the surface  (due to ir-regularities) against motion of a 
body by the system to  moving the system.
?In fluid mechanics, resistance offered by the fluid (within the system layer to 
layer) itself is known as Viscosity.
?Due to the frictional force our effort to do particular work is being increased.
?Friction is must for the operation of Belt, Clutch, Screw Jack, Brake, Automobile 
etc.,
?Friction is undesirable in the case of Bearing.
?Power lost due to friction is converted in to heat.
Page 5


• Friction is a force between two surfaces that are
sliding, or trying to slide across one another, for
example when you try to push a toy car along the
floor.
• Friction always works in the direction opposite from
the direction of the motion of the object. It always
parallel to the plane of contact.
Moving
Friction
Friction
• The Major Cause of the friction is the interlocking of
minute projections on the surfaces which opposes the
relative motion.
Reason for Friction
The amount of friction depends on the materials from 
which the two surfaces are made. The rougher the surface, 
the more friction is produced
Types of Friction
FRICTION
?The Resistance offered by the surface  (due to ir-regularities) against motion of a 
body by the system to  moving the system.
?In fluid mechanics, resistance offered by the fluid (within the system layer to 
layer) itself is known as Viscosity.
?Due to the frictional force our effort to do particular work is being increased.
?Friction is must for the operation of Belt, Clutch, Screw Jack, Brake, Automobile 
etc.,
?Friction is undesirable in the case of Bearing.
?Power lost due to friction is converted in to heat.
The Laws of Dry Friction
• Maximum static-friction force and kinetic-
friction force are:
- proportional to normal force
- dependent on type and condition of 
contact surfaces
- independent of contact area