In the air, there's nothing holding the body of the helicopter still - so the rotor blades spin one direction, but the torque applied to spin the rotors tries to spin the body of the helicopter in the opposite direction. The little rotor on the tail helps keep the body of the helicopter pointed in the same direction.
This picture develops a clear understanding.
Balance on a bicycle is a matter of constantly correcting against falls, and it's easier when the speed is higher because the inertia of moving forward overcomes the need for corrective actions.
Matter is anything that possesses mass, occupies space and may be perceived through one or more senses.
The physical divisions of matter are:
1. Solid : Solid matter is composed of tightly packed particles. A solid will retain its shape; the particles are not free to move around.
2. Liquid : Liquid matter is made of more loosely packed particles. It will take the shape of its container. Particles can...
