Question

Which of the following forces always acts against the applied force?
A. Muscular force
B. Mechanical force
C. Chemical force
D. Frictional force

Answer 1

We have to check each and every force, and compare that is the force opposing the applied force or not. We can take the condition of two bodies moving over each other and force is applied on one body but the surface of the other body is opposing the motion.

Complete step by step answer:
When two bodies slide over each other then there is a force acting between them that force opposes the body to move this force is known as friction.
There are four types of friction:
Static friction, Rolling friction, Fluid friction, Sliding friction.
We know that frictional force is the force that only offers resistance to a relative motion between two surfaces whether it is a liquid, solid or gas against each other.
Thus the force always acting against the applied force is known as frictional force.

So, the correct answer is “Option D”.

Additional Information: Static or frictional electricity is a type of electricity that is produced whenever any two suitable substances like hair and comb, glass rod and silk, sealing wax, and wool are rubbed together vigorously over each other to develop a charge which is small in magnitude. It is also known as triboelectricity.
Few uses of static or frictional electricity include painting, Xerox machines, and pollution control. In Xerox machines or printers the ink is attracted by the static electric charges. Static electricity has a property of attracting small dust particles towards itself thus it is used to control pollution.

Note: When any object is in the air only two major forces act on the body one is the frictional force of the air that is the friction that the air has and another force is the earth that tries to pull the body towards itself that is the gravitational force.