Normal Force Formula: Definition and Examples

The normal force, also known as the normal reaction force, is a contact force. A normal force cannot be exerted on two surfaces that are not connected to one another. Consider a table and a container; when they are not in contact, they cannot exert normal force on one another. When two objects come into contact with one another, they exert normal force on each other vertically to the contacting surface. In this case, normal denotes a perpendicular.

During deceleration, the normal force is equal to the weight of the body. The location of the body on the ground determines when the body is about to fall. F\[_{n}\] represents normal force and is measured in terms of N. (Newtons).

normal force Formula
normal force Formula

Concept of Normal Force 

The normal force is precisely defined as the component of force that is vertical to any contact surface. It also determines how much force the body exerts on the ground. The normal force is equal to the object’s weight only if the object is not accelerating, i.e. decelerating. When an object is about to fall, the position in which the object falls on the ground determines the outcome. It is represented by the symbol F\[_{n}\] and is given in newtons (N).

Normal Force Formula

An object during rest on the flat surface the normal force and it is denoted by F\[_{n}\] is given by F\[_{n}\] = mg

Where,

g is the Gravitational Force

m is the mass 

A force acting on a falling object it drops at an angle equal to θ, then the F\[_{n}\] is said to be greater than the formulated weight,

F\[_{n}\] = mg + F sin θ

Where,

the normal force is F\[_{n}\]

the mass of the body is m

gravitational force is g

the angle with which body falls is denoted by θ

A force tugs the object towards upward,  then F\[_{n}\] is less than its weight

F\[_{n}\] = mg – F sin θ

Where,

the normal force is F\[_{n}\]

the mass of the body is m

gravitational force is g

the angle with which body moves up is denoted by θ

An object placed on an inclined plane then normal force F\[_{n}\] is

F\[_{n}\] = mg cos θ

Where,

the normal force is F\[_{n}\]

the mass of the body is m

gravitational force is g

The angle of the inclined surface is denoted by θ

Normal Force Examples

Examples of Normal Force-

Because of their weights, contact objects exert force on each other. Because of its weight, the book exerts a force on the table, and the table exerts a force on the book. This force is referred to as the “normal force,” and it has the same magnitude as the applied force but is directed in the opposite direction (weight of the book).

In general, we say that normal force is the reaction to the perpendicular force exerted on it in various situations. We will look at various examples of the normal force.

FAQs

How do I calculate normal force?


The weight of an object equals the mass of the object multiplied by the acceleration of gravity. Multiply the two values together. In order to find the normal force, you need to multiply the weight of the object by the cosine of the angle of incline.

What is the normal force in the friction formula?


coefficient of friction, the ratio of the frictional force resisting the motion of two surfaces in contact to the normal force pressing the two surfaces together. It is usually symbolized by the Greek letter mu (μ). Mathematically, μ = F/N, where F is the frictional force and N is the normal force.

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