Questions tagged [friction]
The resistance a surface or object encounters when moving over another.
2,851 questions
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0 answers
64 views
Science Olympiad Machines question [closed]
My son is practicing with his high school Science Olympiad team and came across this question: His source includes an answer, without explanation, that the coefficient of friction is $\mu\approx3.3$. ...
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0 votes
2 answers
102 views
How could one show that kinetic friction is a non-conservative force?
The question is not to talk about why kinetic friction is non-conservative, but rather if there is a way that I could show mathematically that the work done by kinetic friction is path-dependent?
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1 vote
1 answer
186 views
Is stiction absolute or an approximation for short durations?
There is a proverb "Water dripping day by day wears the hardest rock away". I could not easily find any info for not absolute and any discussion why, hence I ask here. Is static friction ...
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0 votes
2 answers
220 views
A body has acceleration when the net force acting on it is equal to 0 according to Newton's 2nd law
There is a block $A$ on the table; the friction between the table and the block is not taken into account. A cube $B$ lies on the block, the coefficient of friction between the cube and the block is $...
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0 votes
5 answers
86 views
Can a short, strong increase of normal force make a sliding block reverse direction on a fixed surface?
A block is sliding to the right on a horizontal, stationary platform. For a very short time I press straight down on the block so the normal force—and therefore the friction—briefly becomes large. I ...
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0 votes
1 answer
42 views
Can kinetic friction while sliding down a ramp be equal to static friction? [closed]
The correct answer B shows that velocity is constant for Scenario 1. This means that, along the incline, acceleration = 0 and F_net = 0. Then, kinetic friction (Fk) and the parallel component of ...
- 13
14 votes
2 answers
1k views
Why doesn’t a rolling wheel keep accelerating if friction torque is in the same direction as rotation?
When a wheel rolls without slipping, friction acts backward at the point of contact with the ground. However, the torque due to that friction seems to be in the same direction as the wheel’s rotation. ...
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2 votes
0 answers
117 views
Why do we have a horseshoe curve in this railway section on only one track?
Just north of the Ponpadi station on the Chennai-Renigunta railway line lies a breathtaking horseshoe curve: I am quite aware of the reason why horseshoe curves exist on railway lines, due to the ...
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1 vote
0 answers
76 views
Da Vinci bridge: why outer steps stay in place?
Consider Da Vinci's famous "boltless" bridge. (See image below*) Consider in particular an implementation with a significant 'arc', i.e. both ends start with a significant incline. How to ...
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0 votes
3 answers
238 views
Does rubbing hands decreases internal energy?
So, I took an exam yesterday and it asked, "Rubbing hands ___ internal energy" and it gave the options: Increases, Decreases, Does not affect. My though process was that the two hands exert ...
1 vote
2 answers
135 views
What is the location of the resultant friction force?
My question is as follows: Consider a crate, but it's acting on a force $P$. It doesn't move or tip over. We calculate the location of the normal force based on equilibrium conditions, and we ...
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8 votes
2 answers
2k views
What keeps cotton thread together and why does old cotton thread becomes easily torn apart?
One of my old t-shirts recently got a tear. When I pull near the tear, it easily tears more and more apart. When I looked through 20x magnification, I don't see difference of thread in place where it ...
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0 votes
1 answer
85 views
Rolling resistance vs rolling friction [closed]
recently i had to go for wheel dynamic problem to choose a actuator and since my wheel is not steerable i choose 2d assumption. and i just faced a confusion in a rolling wheel if both surface and ...
1 vote
0 answers
77 views
Cricket ball trajectory calculation [closed]
I want to calculate the trajectory of a cricket ball using the TV camera, and be able to model the ball after it pitches. However, I am finding it difficult to accurately get the values of bounce ...
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0 votes
0 answers
29 views
Does friction depend on area of contact between the bodies in relative motion? if it does why is it not in f=coefficient×normal? please explain [duplicate]
let us assume two cuboid with same material,same surface in contact and same weight but different orientation in space w.r.t contact surface (One is in contact vertically ,other horizontally). will ...
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