Friction Lab
Friction
Friction
Peter Jeschofnig, Ph.D.
Version 09-1.01
Objectives
To provide an understanding of the concept of friction, and
To calculate the coefficient of friction of an object by two methods.
Materials From:
Label or
Box/Bag:
Student
Provides
Qty Item Description:
1
1
1
1
1
1
1
From LabPaq
Ramp board: 3 - 4 feet long, 10 cm wide
Can of soft drink or item of similar weight
Friction block set-PK
Protractor
Scale-Spring-500-g
Tape measure, 1.5-m
Tape measure, 3-m
Discussion and Review
Whenever a body slides along another body a resisting force is called into play that is known as friction. This is a very important force and serves many useful purposes. A person could not walk without friction, nor could a car propel itself along a highway without the friction between the tires and the road surface. On the other hand, friction is very wasteful. It reduces the efficiency of machines because work must be done to overcome it and this energy is wasted as heat. The purpose of this experiment is to study the laws of friction and to determine the coefficient of friction between two surfaces.
THEORY
Friction is the resisting force encountered when one surface slides over another. This force acts along the tangent to the surfaces in contact. The force necessary to overcome friction depends on the nature of the materials in contact, on their roughness or smoothness, and on the normal force but not on the area of contact or on the speed of the motion. We find experimentally that the force of friction is directly proportional to the "normal force." When an object is sitting on a horizontal surface the normal force is just the weight of the object. However, if the object is on an incline then it is not equal to the weight but is calculated by N= mg cos θ. The constant of proportionality is called the coefficient of friction, µ. When the contacting surfaces are actually sliding one over the other the force of
Friction
Peter Jeschofnig, Ph.D.
Version 09-1.01
Objectives
To provide an understanding of the concept of friction, and
To calculate the coefficient of friction of an object by two methods.
Materials From:
Label or
Box/Bag:
Student
Provides
Qty Item Description:
1
1
1
1
1
1
1
From LabPaq
Ramp board: 3 - 4 feet long, 10 cm wide
Can of soft drink or item of similar weight
Friction block set-PK
Protractor
Scale-Spring-500-g
Tape measure, 1.5-m
Tape measure, 3-m
Discussion and Review
Whenever a body slides along another body a resisting force is called into play that is known as friction. This is a very important force and serves many useful purposes. A person could not walk without friction, nor could a car propel itself along a highway without the friction between the tires and the road surface. On the other hand, friction is very wasteful. It reduces the efficiency of machines because work must be done to overcome it and this energy is wasted as heat. The purpose of this experiment is to study the laws of friction and to determine the coefficient of friction between two surfaces.
THEORY
Friction is the resisting force encountered when one surface slides over another. This force acts along the tangent to the surfaces in contact. The force necessary to overcome friction depends on the nature of the materials in contact, on their roughness or smoothness, and on the normal force but not on the area of contact or on the speed of the motion. We find experimentally that the force of friction is directly proportional to the "normal force." When an object is sitting on a horizontal surface the normal force is just the weight of the object. However, if the object is on an incline then it is not equal to the weight but is calculated by N= mg cos θ. The constant of proportionality is called the coefficient of friction, µ. When the contacting surfaces are actually sliding one over the other the force of