The direction of friction when the bicycle is moving

Analyze the reasons for the rotation of the two wheels, and you will understand.

When pedaling the bike, the rear wheel provides power because the chain is tethered to the rear axle. The rear wheels are actively moving, not because of friction, and the part of the wheel that is in contact with the ground is moving backwards, so the friction should be forward in the opposite direction. It's a different story with the front wheels, it's passive.

Originally, it was not moving, but when pedaling, the front wheel axle was affected by the forward force, and the movement trend was forward, at this time, the friction force was reversed backwards, forming a moment that caused the front wheel to rotate, that is, the front wheel will roll forward because of the existence of friction, which is different from the rear wheel. This is the situation when riding.

When you push the cart, neither the front wheel nor the rear wheel is active, both axles are affected by a force from your forward, so the situation is the same as the front wheel mentioned above, the friction force is backwards.

Physical laws are not dogmas, but should be analyzed on a case-by-case basis.

The rear wheels are the power wheels, which are to give you power, so it is the friction that you provide the traction that is forward, and the driven wheels of the front wheels, of course, backwards.

First, riding a bicycle makes both wheels turn backwards, so both wheels move forward.

If there is no friction, the rear wheel keeps turning backwards when riding a bicycle, and the front wheel does not move;

With friction, the rear wheels move forward, and the front wheels move forward. Because there is friction, the ground prevents the rear wheels from turning backwards, so the friction is forward, and the ground prevents the front wheels from standing still, giving it a backward friction force that makes the front wheels also turn backwards, so the front wheels also move forward.

When we ride on a bicycle, there is friction between the bicycle and the road surface because the person and the bicycle have pressure on the ground, and the tire and the ground are not smooth, but why does the bicycle move forward? Again, this is caused by the friction between the rear wheels and the ground, and the direction of this friction is forward. So what does the friction of the front wheel do?

Hinder the movement of the car! It goes in the opposite direction to the direction in which the bicycle is traveling. It is these two forces that are equal in magnitude and opposite in direction, so the bicycle moves at a uniform speed.

However, when people push their bikes forward on the ground, the direction of friction between the front and rear wheels is backwards. So who is in balance with these two forces? The friction of the foot against the ground forward!

Discuss it on a case-by-case basis

Pushing and walking, the direction of power is of course forward, and the object of force is a person, so the friction of the front and rear wheels is backward.

2 Riding and walking, the power is also forward, and it is the rear wheel that applies the force (of course, it is ultimately the person who applies the force, and there are chains and pulleys, which change the direction of the inside, and it is considered that the direct force is applied to the rear wheel) This is, the friction of the driving wheel is forward, because he has a tendency to move backwards, and the friction of the driven wheel is backward, because he is moved by the thrust of the driving wheel, and the friction is the opposite.

1. When a person rides a bicycle, the chain drives the rear wheel, and the contact point between the rear wheel and the ground is forced backward, and the friction force plays a reaction force, so the friction force is forward; The front wheels turn forward under the drive of sliding friction, which is equivalent to the wheels not moving to pull the ground back, and the friction force plays a force, so the direction is backward.

2. The friction of the two wheels is backward when the person pushes the car, and the front wheel is the same as the force on the front wheel when the person rides, and the hind foot is pushed backward when the person walks, and the friction force plays a reaction force, so the friction force is forward; If there is no friction, the person will not be able to move forward, a bit like the feeling of walking on ice, the friction of the front foot acts as a reaction force, and the direction of the friction is backwards.

1. When a person rides a bicycle, the chain drives the rear wheel, and the contact point between the rear wheel and the ground is forced, and the friction force plays a reaction force, so the friction force is forward; The front wheels turn forward under the drive of sliding friction, which is equivalent to the wheels not moving to pull the ground back, and the friction force plays a force, so the direction is backward.

Answer: 2. The friction of the two wheels when the person pushes the cart is backward, and the front wheel is stressed in the same way as when the person rides, and the hind feet are pushed backward when the person walks, and the friction force plays a reaction force, so the friction force is forward; If there is no friction, people will not be able to move forward, a bit like walking on the ice, the friction of the front foot acts as a reaction force, and the friction direction is backwards.

1. When a person rides a bicycle, the chain drives the rear wheel, and the contact point between the rear wheel and the ground is forced backward, and the friction force plays a reaction force, so the friction force is forward; The front wheel turns forward under the drive of sliding friction, which is equivalent to the wheel not moving to pull the ground back, and the friction force plays a force so the direction is backward.

2. The friction of the two wheels is backward when the person pushes the car, and the front wheel is stressed in the same way when the person rides the bicycle, and the rear foot is pushed backward when the person walks, and the friction force plays a role in the reverse pulling and dismantling force, so the friction force is forward; If there is no friction, the person will not be able to move forward, a bit like the feeling of walking on ice, the friction of the front foot acts as a reaction force, and the direction of the friction is backwards. Eliminate dates.

1. The direction of the friction of the bicycle.

2. The direction of friction on a bicycle.

3. The direction of friction when riding a bicycle.

4. The direction of friction when the bicycle is walking.

1.The rear wheel is a driving wheel, as long as the foot pedals, it always rotates counterclockwise, and at the tangent point with the ground, there must be a backward relative movement tendency, and it will be subject to the forward friction force exerted by the ground.

2.This friction is what keeps the whole bike moving forward, and it's beneficial.

3.The rear wheel is a driven wheel, and the bicycle does not move as a whole, so it does not turn.

4.When the rear wheel rotates to make the whole vehicle move forward, the front wheel has a forward relative movement tendency at the tangent point with the ground, and it will be subjected to the backward friction force exerted by the ground, so as to rotate.

5.This friction is the resistance of the whole bike forward, which is harmful.

The rotating shaft of the bicycle uses rolling friction instead of sliding friction to reduce friction.

。Generally, marble-disc bearings are used.

When riding a bicycle hail, the rear wheel is the driving wheel, and the lower posture of the rear wheel has a tendency to slide backward at the contact with the ground, and the direction of friction is forward; There is a tendency for the front wheels to slide forward where they are in contact with the ground, and the direction of friction is backwards.

When pushing the cart, the front and rear wheels have a tendency to slide forward at the contact with the ground, and the friction source and friction force are backward.

When riding a bicycle, the rear wheel is driven by the chain skin disposition bar, and the rear wheel is the power wheel, which is powered forward by the ground. It can also be understood that the rear wheels rotate, and the ground gives the rear wheels a forward power in order to "hinder" the rotation.

When pushing a bicycle, the front and rear wheels are both resistance wheels, which are subject to backward resistance from the ground. It can also be understood as the rotation of the rear wheels of the trolley due to backward friction.

There are two scenarios.

1. When you pedal with your foot, the friction of the front wheel is pulled backwards. The friction of the rear wheels is forward. Stupid.

2. When you don't board the pedal, the friction between the front wheel and the rear wheel is backward (the above direction is the direction of the friction force of the ground acting on the wheel).

Because if you want your bike to move forward, you have to be affected by force! And the only external force acting on the bicycle is friction (except, of course, when you push the bicycle with your hands).

Because you are going forward, all the frictional force f should be forward! (because the object is moving in the same direction as the force being applied).

The rear wheels of the bicycle are the driving wheels and will experience the friction force forward, and the front wheels are driven wheels, and on the contrary, the friction of the rear wheels is greater than that of the front wheels .

It is equivalent to that when a person walks on the ground, he must be subjected to forward friction, and if you kick the ground backwards, the ground in turn will give you forward friction!

Hehe, I don't know if it's clear).

The front wheel is generally driven by the wheel!

The rear wheels push the front wheels, just like a person pushing a box! Friction is naturally opposite to the direction of motion!

The rear wheels should not be said to be rearward-facing relative to the ground! Rather, it should be said that there is a backward trend of movement, and the direction of friction is opposite to the direction of the movement trend!

Because friction and the direction of movement are opposites (the basic idea of friction, you have to listen carefully in class, the teacher must have talked about it!) ）