Question

Why is the frictional force acting on the front tyre of a bicycle backwards?(while pedalling)

Answer 1

Let’s look at the back wheel first. The back wheel came in contact with the road, forms some bonds with it and through those bonds pushed the road backward. Parallel to the surface right? This is kind of what we call, or this is exactly what we call friction. So the back wheel applied a frictional force on the road backwards. By Newton’s third law, the paper must have applied a frictional force on the back wheel forwards. So the frictional force on the back wheel is forwards. Now that’s interesting. What about the front wheel? Is it going to be the same? If you look at the front wheel, it did form some bonds with the road already and then the road began to move that way thereby pulling the, the front wheel that way. Now this front wheel is feeling a pull from the road in a direction parallel because of the contact. That’s exactly friction. So that force that we mark there is the friction on the front wheel and that’s backwards.