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A Physics Enthusiast
If friction is independent of area of contact, how do less inflated tires of a bicycle experience more resistance towards motion than the well inflated tires?
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https://en.wikipedia.org/wiki/Rolling_resistanceT13091999 said:If friction is independent of area of contact, how do less inflated tires of a bicycle experience more resistance towards motion than the well inflated tires?
Take an uninflated tyre and 'knead' it with your hands. When you cycle on a soft tyre, you are actually doing this to every bit of the tyre as it comes into contact with the ground. A hard tyre may rattle your teeth but it takes much less energy.T13091999 said:If friction is independent of area of contact, how do less inflated tires of a bicycle experience more resistance towards motion than the well inflated tires?
I have failed to understand this. Do you mean that the deformation of the tyre takes away the "effort" ? (Sorry for the not-so-proper terminology)sophiecentaur said:Take an uninflated tyre and 'knead' it with your hands. When you cycle on a soft tyre, you are actually doing this to every bit of the tyre as it comes into contact with the ground. A hard tyre may rattle your teeth but it takes much less energy.
P.S. Steel wheels on steel rails are highly efficient.
The forward motion of the bicycle requires continual deformation of the tires as they roll. This deformation consumes energy beyond what is required to overcome friction.A Physics Enthusiast said:I have failed to understand this. Do you mean that the deformation of the tyre takes away the "effort" ? (Sorry for the not-so-proper terminology)
The hysteresis in the deformation involves a loss of energy. So the deformation takes away Energy. The word "effort" is used to describe a Force so it is not appropriate to apply it here, I think. Best to talk in terms of Work Done and work returned to the system.A Physics Enthusiast said:I have failed to understand this. Do you mean that the deformation of the tyre takes away the "effort" ? (Sorry for the not-so-proper terminology)
Did you read the link in post #2?A Physics Enthusiast said:Do you mean that the deformation of the tyre takes away the "effort"?
Yes. Wikipedia says that deformation of the tyres contributes to rolling friction. I got confused as I wasn't able to link that concept with the concept of friction being independent of area.A.T. said:Did you read the link in post #2?
Some wikipedia articles are quite good, some not so much, and some are generally OK but carelessly written so can be confusing. You've been victimized by one of that last kind.A Physics Enthusiast said:Yes. Wikipedia says that deformation of the tyres contributes to rolling friction. I got confused as I wasn't able to link that concept with the concept of friction being independent of area.
Yes, energy is lost in the continuous deformation of the underinflated tire as it rotates. It has nothing to do with the friction between the tire and the road. Have you been able to start understanding this effect now because of the responses in the thread?A Physics Enthusiast said:I have failed to understand this. Do you mean that the deformation of the tyre takes away the "effort" ?
Yes. I need some time (exams are going on).berkeman said:Have you been able to start understanding this effect now because of the responses in the thread?
Why are you trying to link it to something you learned about "friction"? The wiki article explains right at the start why "rolling friction" is a misnomer.A Physics Enthusiast said:Yes. Wikipedia says that deformation of the tyres contributes to rolling friction. I got confused as I wasn't able to link that concept with the concept of friction being independent of area.
Friction is the force that resists the relative motion between two surfaces that are in contact with each other. It is important in motion because it can either hinder or aid the movement of objects and is a key factor in determining the amount of energy needed for an object to overcome resistance and move.
Tire inflation affects friction and resistance by altering the contact between the tire and the road surface. When tires are properly inflated, they have a larger contact area with the road, resulting in more friction and better traction. This can reduce resistance and improve the overall efficiency of motion.
The relationship between tire pressure and friction is inverse - as tire pressure increases, the contact area between the tire and road decreases, resulting in less friction. This can lead to reduced traction and increased resistance, making it harder for the vehicle to move.
Proper tire inflation can significantly impact fuel efficiency. Under-inflated tires can cause increased resistance and drag, leading to a decrease in fuel efficiency. On the other hand, over-inflated tires can also result in reduced fuel efficiency due to the decreased contact area and increased wear and tear on the tires.
The impact of tire inflation on resistance can be measured through experiments or simulations that compare the performance of tires at different inflation levels. This can include measuring the distance a vehicle can travel with different tire pressures, as well as the amount of energy needed to overcome resistance and maintain a constant speed. Additionally, specialized tools such as dynamometers can be used to measure the force and resistance experienced by tires at different inflation levels.