Question

Hey there....
Please define these topics ....☺

i) Define Friction
ii) Direction of force
iii) Cause of Friction
iv) Factors affecting friction ​

Answer 1

1.Friction is the resistance to motion of one object moving relative to another. It is not a fundamental force, like gravity or electromagnetism. Instead, scientists believe it is the result of the electromagnetic attraction between charged particles in two touching surfaces.

2.Direction of force means that the force acts in the same direction in which the force is applied and force is also a vector quantity The SI unit of force is newton (N)

3.The causes of this resistive force are molecular adhesion, surface roughness, and deformations. Adhesion is the molecular force resulting when two materials are brought into close contact with each other.

4.Factors Affecting Friction

Friction depends partly on the smoothness of the contacting surfaces, a greater force being needed to move two surfaces past one another if they are rough than if they are smooth. However, friction decreases with smoothness only to a degree; friction actually increases between two extremely smooth surfaces because of increased attractive electrostatic forces between their atoms. Friction does not depend on the amount of surface area in contact between the moving bodies or (within certain limits) on the relative speed of the bodies. It does, however, depend on the magnitude of the forces holding the bodies together. When a body is moving over a horizontal surface, it presses down against the surface with a force equal to its weight, i.e., to the pull of gravity upon it; an increase in the weight of the body causes an increase in the amount of resistance offered to the relative motion of the surfaces in contact.

Answer 2

Answer:

I). it is a force that help us to move

ii). Any thing that allows us to do anything is called force

iii). less friction can cause car accident

iv). oil