How to find the coefficient of friction?

AI Thread Summary
To find the coefficient of friction, the discussion revolves around applying Newton's second law, where the net force is the difference between the applied force and the friction force. Given a mass of 3.2 kg and an applied force of 22.8 N resulting in an acceleration of 3.02 m/s², the equations of motion are used to derive the coefficient. The key equations presented include ma = FA + FfK and ma = FA - Mmg, highlighting the relationship between forces. A correction is noted regarding algebraic manipulation, specifically the need to divide all terms by mg to accurately derive the coefficient. Understanding these equations and their proper application is crucial for calculating the coefficient of friction.
trASHf
Messages
5
Reaction score
0
Homework Statement
Unknown object has a mass of 3.2kg on steel plank.

Add force:
|FA|=22.8N
|a|=3.02m/s^2

What is the material?
Relevant Equations
Newton's Second Law - sum of all forces = mass * acceleration = ...
GR (bold = mathematical convention)
m = 3.2kg
|applied force| = + 22.8 N
|acceleration| = + 3.02 m/s^2

FBD-hypothetical
^ normal force
|
friction force <-----*-----------> applied force
|
gravitational force

A
ma = FA + FfK
ma = FA -Mmg
ma/mg = FA - M
ma/mg - FA = -M
 
Physics news on Phys.org
Hi,

Can you imagine it is hard to make sense of this ? Read what you posted
 
Last edited by a moderator:
BvU said:
Hi,

Can you imagine it is hard to make sense of this ? Read what you posted

other than the attempted solution I put there, no I don't think it's hard to make sense of this.
 
trASHf said:
ma = FA + FfK
ma = FA -Mmg
ma/mg = FA - M
ma/mg - FA = -M
Your algebra is faulty when you go from the second equation to the third. You need to divide all the terms on the right side by mg.
 
  • Like
Likes trASHf
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

Coefficient of Friction when Normal Force is Reduced [HS]
Replies
5
Views
2K
Coefficient of kinetic friction of a block sliding across the ceiling
Replies
7
Views
1K
Calculating force needed to push sled down incline
Replies
4
Views
3K
Static Friction Between a Box and the Floor
Replies
11
Views
3K
Calculate the coefficient of static & kinetic friction
Replies
8
Views
7K
Mechanical Physics: Coefficient of Friction
Replies
20
Views
3K
Applying Newtons Laws: Incline, static friction, kid on sled
Replies
8
Views
2K
How much work done by friction when a box w/apparent mass...?
Replies
4
Views
2K
How to find Coefficient of Friction w/ Fa and mass?
Replies
5
Views
4K
What are the forces acting on a child pulling a wagon up an inclined hill?
Replies
3
Views
4K

Hot Threads

Recent Insights

Back
Top