What is the movement of a bicycle wheel? The
② why can the bike advance? When we ride on the bike, because people and bicycles on the ground pressure, tires and the ground is not smooth, so there is friction between the bike and the road, but to ask why the bike to move forward? This is also dependent on the friction between the rear wheel and the ground, the direction of this friction is forward. What is the frictional force of the front wheel? Hinder the movement of the car! Its direction and the direction of the bicycle forward. It is the size of these two forces equal, the opposite direction, so the bike for uniform movement. However, when people push the bike on the ground forward, the front wheel and rear wheel friction direction are back. Who and the two forces balance it? Feet on the ground friction forward!
④ where the bike has a steel ball? Why is it? In the bike's front axle, axle, rear axle, handlebar rotation, pedal rotation and other places, are a steel ball.
③ after the brake, why can stop the bike? Brake, the friction between the brake pads and the wheel, will hinder the rotation of the rear wheel. The greater the pressure on the brake, the greater the pressure on the rim, the greater the friction will be generated, the rear wheel to rotate the slower. If completely stopped, then the friction between the rear wheel and the ground becomes sliding friction (the original rolling friction, the direction forward), the direction backward, hinder the movement of the bike, so stopped.
① bicycle tires why there should be uneven pattern of friction with the size of two factors: the size of the pressure, the roughness of the contact surface. The greater the pressure, the greater the friction; contact surface more rough, the greater the friction. Bicycle tires are uneven, which is by increasing the degree of roughness between the bike and the ground to increase the friction, the purpose is to prevent the bike skid.
