Hardly. There are a few atoms of gas in outer space, but their density is so low that for most practical applications, they can be ignored.
Friction.
Friction.
The direction of friction of a rolling body is in opposite direction to the motion of the rolling body.
Friction always opposes the motion of a body by acting in the opposite direction to its motion.
The friction experienced by a body when in motion is called kinetic friction. This type of friction occurs between two surfaces that are in contact and moving relative to each other. The amount of kinetic friction depends on the materials of the surfaces and the force pressing them together.
The force on Earth that always opposes the motion of a body when it is in motion is called friction.
Friction. More specifically, if the body remains at rest then the opposing force is known as static friction. Whereas, if the body is in motion it is known as kinetic friction.
Yes, friction can involve static friction when two surfaces are not moving relative to each other, and kinetic friction when the surfaces are in motion. Both types of friction occur due to the interaction between the surfaces at a microscopic level.
when the friction is absent during the motion there may be a chance of skidding occurs. there should be some amount of friction during the motion of any body also there should not be too much friction as it decreases efficiency of the vehicle.
by applying water on the floor.
In the direction opposite to that of the sliding body.
When a body slides or rolls over another body, the force of friction is called kinetic friction. This friction arises due to the contact between the surfaces of the two bodies and opposes the relative motion between them.