Conceptual Question about Static Friction

In summary, the conversation revolved around the question of why the equation for the coefficient of static friction is independent of the weight of the block. The equations ΣFx=Fapplied-fs=0 and ΣFy=Fn-mgcosθ=0 were mentioned, but it was noted that μs=height/length is not the correct definition of the coefficient of friction. The reasoning for the independence of weight was discussed, with the conclusion that the coefficient of static friction is proportional to the ratio of height over length, and therefore weight does not play a role in this matter. However, it was noted that the definition of the coefficient of friction should be referenced for a proper answer.
  • #1
TyroneTheDino
46
1

Homework Statement


Today we were studying a block on an incline and determining the angle needed for the block to start sliding. The question asked is: Why is the equation for the coefficient of static friction independent of the weight of the block?

Homework Equations


ΣFx=Fapplied-fs=0
ΣFy=Fn-mgcosθ=0
μs=height/length

The Attempt at a Solution


My reasoning is that because the coefficient of static friction is reliant by height over length, weight has no involvement in this matter. If you double the weight of an object on an incline, the coefficient of static friction would still be proportional to coefficient if you were to leave the weight the same. I feel like I am on the right track, I just feel like my reasoning is missing proof.
 
Physics news on Phys.org
  • #2
TyroneTheDino said:
Why is the equation for the coefficient of static friction independent of the weight of the block?
That's strange wording. I would have expected a question like ""why is the coefficient of static friction independent of the weight of the block?"
Is it referring to the equation you quote, μs=height/length? That is not the definition of the coefficient of friction. (It's none of the equations you listed.) To answer the question properly, you need to reference the definition.
 

FAQ: Conceptual Question about Static Friction

1. What is static friction?

Static friction is a type of force that prevents two surfaces from sliding past each other when they are in contact and at rest. It is the force that must be overcome in order for an object to start moving on a surface.

2. How is static friction different from kinetic friction?

Static friction occurs when an object is at rest, while kinetic friction occurs when an object is in motion. The amount of force required to overcome static friction is typically greater than the force required to overcome kinetic friction.

3. What factors affect the strength of static friction?

The strength of static friction is affected by the type of surfaces in contact, the force pressing the surfaces together, and any roughness or imperfections on the surfaces.

4. Can static friction ever be greater than kinetic friction?

Yes, in some cases static friction can be greater than kinetic friction. This can happen when there is a significant difference in the roughness or adhesiveness of the surfaces, or when there is a large force pressing the surfaces together.

5. How can static friction be reduced?

Static friction can be reduced by using a lubricant, such as oil or grease, to make the surfaces more slippery. It can also be reduced by increasing the surface area of contact between the two surfaces, or by reducing the force pressing the surfaces together.

Similar threads

How can I determine the instant the block overcomes static friction?
2
Replies
61
Views
1K
Static friction coefficient for a crate in the back of a truck
Replies
6
Views
2K
Pulley with friction, how to get the friction in the pulley?
Replies
23
Views
2K
Static Friction Question — A wood block sliding on a tabletop
Replies
7
Views
1K
Statics and friction -- Two articulated rods connected to blocks
Replies
13
Views
1K
Is there any friction in this case?
Replies
12
Views
791
Magnitude of the force of static friction
Replies
2
Views
2K
Static friction of a block on an incline?
Replies
1
Views
1K
What is the static friction force acting on the object?
Replies
2
Views
1K
Static friction force: Consider a block on a sheet of paper....
Replies
12
Views
2K

Hot Threads

Recent Insights

Back
Top