Electrons. That is how static charge is built. Some of the electrons of one object
move to the other, creating a negative charge where the electrons have built up,
and a positive charge where the electrons have vacated.
Yes, gravel does have friction because of the rough and irregular surface of its individual particles. When objects move across gravel, the contact between the particles and the object creates resistance, which we perceive as friction.
Objects with the most surface area.
Static friction is higher than kinetic friction because an object at rest has many electrostatic forces between its particles and particles on the surface on which the object sits. An object in motion also has these forces, but they are much less since there is less time for particles to form bonds as they move past each other. Ultimately the coefficient of friction is a measure of the 'stickiness' between two objects, that is the ease in which the objects can bond with each other.
The force that opposes motion when moving objects over a surface is called friction
Large particles have less total surface area, so caused less friction then the smaller particles do
The 3 types of friction are static friction (force between stationary objects), kinetic friction (force between moving objects), and rolling friction (force between a rolling object and a surface). Friction is the resistance that one surface or object encounters when moving over another.
The texture of a surface can affect motion by creating friction. A rough texture can increase friction, making it more difficult for objects to move smoothly across the surface. On the other hand, a smooth texture reduces friction, allowing objects to move more easily.
Kinetic friction is the form of friction that deals with objects that are already in motion. Kinetic friction opposes the motion of an object as it slides or moves across a surface.
The types of friction include static friction (prevents objects from moving), kinetic friction (opposes motion of objects sliding past each other), and rolling friction (resists the motion of objects rolling across a surface).
Friction
The force that opposes motion when moving objects over a surface is called friction
Objects slide because of the forces acting upon them, such as gravity or friction. When an object is on a sloped surface, gravity pulls it downward, causing it to move. The presence of friction between the object and the surface affects how easily the object slides.