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.
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Is there an example in which friction acts in direction of motion. Any special case.
 
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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.
 
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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 .
 
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