How Do You Calculate the Coefficient of Kinetic Friction on an Incline?

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SUMMARY

The coefficient of kinetic friction (μ) for a block sliding down a 30° incline with an acceleration of 1.2 m/s² is calculated to be 0.5. The relevant equations used include the frictional force equation Fr = μ(Fn) and the normal force equation Fn = mg, where g is the acceleration due to gravity (9.8 m/s²). The discussion clarifies that the coefficient of static friction cannot be determined since the block is already in motion, emphasizing the need to analyze the gravitational force components acting on the block.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with frictional force equations
  • Basic trigonometry for incline calculations
  • Knowledge of gravitational force components
NEXT STEPS
  • Study the derivation of the coefficient of kinetic friction using different incline angles
  • Learn about the differences between static and kinetic friction coefficients
  • Explore the effects of varying mass on frictional forces on inclines
  • Investigate the role of acceleration in determining friction coefficients
USEFUL FOR

Physics students, engineers, and anyone interested in understanding friction dynamics on inclined planes.

Bradyns
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A block is sliding down a 30° incline at 1.2ms^-2
Find the coefficient of static friction.
[g=9.8ms^2]

I am stumped..

Some relevant equations:
Fr = μ(Fn)
Fn = mg

Ultimately I got μ=0.5 ---> This was through mashing and playing with some trig.
 
Last edited:
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Bradyns said:
A block is sliding down a 30° incline at 1.2ms^-2
Find the coefficient of static friction.
[g=9.8ms^2]

I am stumped..

I got μ=0.5

If the block is already sliding down the incline, then you don't have the information you need to determine the coefficient of static friction. On the other hand, you do have the information you need to determine the coefficient of kinetic friction. What are the components of the gravitational force on the block in the directions tangent and normal to the incline? Is the block accelerating in the direction normal to the incline? Is the block accelerating in the direction tangent to the incline? What are the force components acting on the block in the direction tangent to the incline? What is the normal force exerted by the incline on the block?
 

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