why we aren't fall down while ride cycle or two wheeler and why we are fall down when we are stopped riding..?

Question

balancing gravity

Answer 1

Because we are not use our legs to keep weselves balanced! LOL!

Answer 2

Yeah, its a cool and strange thing that happens. In physics there are certain things that are always conserved. For instance, if you hit a billiard ball with another billiard ball and the first ball stops what happens to that foward movement of the first ball? Well, we all know that it all went completely into the second ball, which means the second ball will be moving now. This is obvious of course, it is called the conservation of linear momentum. When the wheel spins there is another kind of momentum produced. It is called angular momentum, and it must be conserved just like linear momentum. Of course its a bit more complicated because the direction of the momentum is not foward but perpendicular to the spinning wheel (same as saying parrallel to the ground). To explain why is even more complicated...just take my word for it. If you are on the bike and start to tip over you are trying to change the angular momentum from parrallel to the ground to pointing towards the ground. This is a no no in physics you must alway keep your initial angular momentum whch is parallel . Here is the cool part ..there will be an anuglar momentum created pointing away from the ground so that the combination of the angular momentum away from the ground and towards the ground adds to the original which is parallel. So that you start with parallel and end with parallel..its conseverd. Where dose the other angular momentum come from you ask. I think that it is the same as the billiard ball case but much more complicated to conceptialalize because the directions are perpendicular to the spin. If I am wrong about that point someone let me know. I hope that helps alittle...by the way this is my opinion based years of physics...it could be flawed...im no professor ya know.

Answer 3

In translational motion, Newton's law is every object in the state of uniform motion unless an external force acts on it.
To change the magnitude of velocity or direction of velocity or both, there must be an external force.

In rotational motion similarly, a torque is necessary to change the direction of axis of rotation or the magnitude of angular velocity or both.

Hence one an object is set into rotational motion the direction of axis of rotation will not change, unless an external force produces a torque on the object.

Answer 4

This is because of gyroscopic effect. The rotating wheels act as gyroscopes making the wheels resist a change in position. When the wheels stop rotating you no longer have this force in your favour and you will topple over.

Answer 5

rotational mechanics:
rolling motion occurs due to toppling