Solve Physics HW: Kinetic Friction Coefficient

Thread starter jeffmazz
Start date Sep 25, 2011
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Friction Kinetic Kinetic friction

In summary, the kinetic friction coefficient, denoted as μk, is a dimensionless quantity that represents the resistance between two surfaces in motion. It can be calculated by dividing the magnitude of the kinetic frictional force by the normal force and is affected by factors such as the nature and roughness of the surfaces, normal force, and velocity. It differs from the static friction coefficient and is used in real-world applications such as designing brake systems, determining gear efficiency, and calculating required forces.

Sep 25, 2011

jeffmazz

i feel really dumb but i have this physics homework question i can't get.

a 20kg sled is being pulled across a horizontal surface at constant velocity. the pulling force has a magnitude of 80N at a 30 degree angle above the horizontal. find the coefficient of kinetic friction.

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Sep 25, 2011

btbam91

https://www.physicsforums.com/forumdisplay.php?f=153

FAQ: Solve Physics HW: Kinetic Friction Coefficient

1. What is the kinetic friction coefficient?

The kinetic friction coefficient, denoted as μk, is a dimensionless quantity that represents the resistance between two surfaces when they are in motion relative to each other. It is a measure of the efficiency of converting kinetic energy into heat energy.

2. How is the kinetic friction coefficient calculated?

The kinetic friction coefficient can be calculated by dividing the magnitude of the kinetic frictional force by the normal force acting between the two surfaces. This can be mathematically represented as: μk = Ff / Fn, where μk is the kinetic friction coefficient, Ff is the kinetic frictional force, and Fn is the normal force.

3. What factors affect the value of the kinetic friction coefficient?

The value of the kinetic friction coefficient is affected by several factors including the nature of the surfaces in contact, the roughness of the surfaces, the normal force, and the velocity of the surfaces.

4. How does the kinetic friction coefficient differ from the static friction coefficient?

The kinetic friction coefficient is typically lower than the static friction coefficient, as it represents the resistance between two surfaces in motion. The static friction coefficient, on the other hand, represents the resistance between two surfaces that are not in motion.

5. How is the kinetic friction coefficient used in real-world applications?

The kinetic friction coefficient is used in various real-world applications, such as designing brake systems in cars, determining the efficiency of gears in machinery, and calculating the force needed to slide an object across a surface. It is also an important concept in the field of physics and engineering.