When we are sitting on a cycle which means that the cycle is in rest then we fall either on the left or right direction.But when we are riding a bicycle then we do not fall.Why?

 

When the cycle is in rest and we sit on it, the centre of gravity of system is disturbed. This leads to the cycle bending either towards left or right.

However, when we ride on it, we balance ourselves making the centre of gravity in such a position that the right and left sides are equally balanced.

NOTE: When we sit on a cycle at rest, even then we can balance the cycle by adjusting the centre of gravity.