Friction Friction - - is a force that resists the motion of objects on surfaces. Jennifer Brown
FrictionFriction - - is a force that resists the
motion of objects on surfaces.
Jennifer Brown
What Causes Certain Kinds Of Friction?
Jennifer Brown
Jennifer Brown
Many kinds of friction exist. Can you name any?
› Sliding Friction
› Rolling Friction
› Air Friction
› Static Friction
› Viscous Friction
Jennifer Brown
Jennifer Brown
Jennifer Brown
Jennifer Brown
Friction depends on both surfaces in contact.
When the Hockey puck slides on ice, a thin layer of water between the rubber and the ice allows the puck to slide easily.
Jennifer Brown
Jennifer Brown
How do we identify various types of How do we identify various types of frictional forces?frictional forces?
Friction is a force, measured in newtons (N) just like any other force.
1) Static friction1) Static friction keeps an object at rest from moving.
Jennifer Brown
Jennifer Brown
2) Sliding 2) Sliding frictionfriction
is a force that resists the motion of an object moving across a surface.
Jennifer Brown
Jennifer Brown
How do you think friction even How do you think friction even occurs? What does it depend on?occurs? What does it depend on?
› Friction depends on a material’s properties such as roughness, how clean the surfaces are, and other factors.
› The greater the force squeezing two surfaces together, the greater the friction force.
Jennifer Brown
Jennifer Brown
What could we do in order to increase the frictional forces in this situation?
Jennifer Brown
Jennifer Brown
Jennifer Brown
Jennifer Brown
Unless a force is constantly applied, friction will slow all motion to a stop eventually.
Can we eliminate friction completely?
› No, only reduce it
Jennifer Brown
Jennifer Brown
2012 Maserati GranCabrio Sport2012 Maserati GranCabrio Sport
The friction that results from automobile parts rubbing together during car operation can be extremely great.
This is the reason why the oil in a car must constantly be changed and checked on a regular basis. This reduces the frictional forces.
Jennifer Brown
Jennifer Brown
Grooved tire treads allow space for water to be channeled away from the road-tire contact
point, allowing for more friction in wet conditions.
Jennifer Brown
Jennifer Brown
Shoes are designed to increase the friction between their soles and the ground.
Cleats
Jennifer Brown
Jennifer Brown
How else can friction be beneficial, or How else can friction be beneficial, or possibly harmful?possibly harmful?
Friction changes energy of motion into heat energy.
Jennifer Brown
Jennifer Brown