Frictional Force: Motion Direction Example?

AI Thread Summary
Friction typically opposes the direction of motion, as seen in the case of a tire rolling forward, where it prevents sliding backward. The discussion emphasizes that while friction acts to prevent slipping, it does not contribute to the tire's forward acceleration. When the tire is in motion, the point of contact with the ground remains stationary, resulting in zero work done by friction. The confusion arises from the distinction between opposing sliding motion versus translation motion. Ultimately, friction's role is to maintain traction without contributing to acceleration when the tire is rolling without slipping.
oreo
Messages
81
Reaction score
2
Is there an example in which friction acts in direction of motion. Any special case.
 
Physics news on Phys.org
In Rolling motion , If you have a tire , the frictional force would oppose the tendency of the tire to slide back , that means the frictional force will act to the opposite direction to slide motion and in the direction of the translation motion of the tire,,

Hope it is obvious ,,
 
But we can apply this to every case
Actually in this case also the frictional force is opposing motion of tire. If it is true then the tire should accelerate by itself.
 
  • Like
Likes Maged Saeed
shayan haider said:
But we can apply this to every case
Actually in this case also the frictional force is opposing motion of tire. If it is true then the tire should accelerate by itself.

What do you mean by applying this case to every case ??

The frictional force here is opposing the tendency of the tire to slide back ward when it is moving forward not the translation motion of the tire itself ..,,
 
Maged Saeed said:
What do you mean by applying this case to every case ??

The frictional force here is not opposing the tendency of the tire to slide back ward when it is moving forward not the translation motion of the tire itself ..,,
It would oppose if the tire is stationary but it is in motion. If it is in direction of motion like you are saying then the tire should accelerate. Isn't it
 
Actually we say that the tire is touching the ground with one point , and ,this point is not moving during the contact time and we say that the work done by the frictional force is ZERO since it is not making any sliding to the tire , and that is IF the tire is not sliding .
 
Last edited:

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Thread 'Inclined treadmills and Galilean Invariance'

This has been discussed many times on PF, and will likely come up again, so the video might come handy. Previous threads: https://www.physicsforums.com/threads/is-a-treadmill-incline-just-a-marketing-gimmick.937725/ https://www.physicsforums.com/threads/work-done-running-on-an-inclined-treadmill.927825/ https://www.physicsforums.com/threads/how-do-we-calculate-the-energy-we-used-to-do-something.1052162/
View full post »

Thread 'Derivation of Hamilton's Principle: Questions'

I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
View full post »

Similar threads

B Friction and Newton's laws in car braking systems
Replies
10
Views
2K
B Are frictional forces action forces or reaction forces?
Replies
14
Views
1K
I Question about friction in situation where interface slip occurs
Replies
4
Views
1K
B Static friction needed for rolling without slipping
Replies
4
Views
2K
I Modeling Coulomb Friction for a Moving Point Mass in a Circular Bowl
Replies
20
Views
1K
B Zero acceleration = zero net force?
Replies
33
Views
2K
B Box being pulled up a slope with friction
Replies
3
Views
1K
B How come friction can make a car turn?
Replies
10
Views
2K
B Questions about momentum and force as well as normal force/friction
Replies
35
Views
4K
What determines the direction of static friction forces?
Replies
6
Views
2K

Hot Threads

Recent Insights

Back
Top