Question

What is Scalar Quantity? Or, What do You Mean by Scalar Quantity?

Answer 1

Scalar Quantity : A physical quantity which is described completely by its magnitude (or size) is called a scalar quantity.

Thus, a scalar quantity has only magnitude and no direction.

Example of scalar quantities : The following quantities are scalar quantities.

Length	Distance
Time	Power
Area	Volume
Energy	Speed
Mass	Temperature

​​​​Characteristics of scalar quantities : Scalar quantities show the following characteristics ;

• A scalar quantity can be represented by a number with proper units. The number presents the magnitude (or size) the quantity.

Example -

An object has a mass of 2 kg. The number 2 represent the magnitude of mass, and kg is the unit in which mass is expressed.

• The scalar quantities having similar units get added or subtracted by the usual rules of arithmetic.

Example -

1. If 2 kg of sand is mixed with 1 kg of cement, then the total mass of the mixture will be, 2 kg + 1 kg = 3 kg.

2. If out of 5 metres of cloth, a piece of 2 meters is cut, then the length of the cloth piece left behind will be 5 m - 2 m = 3 m.