Mass

Definition: 

Mass is the measure of the amount of matter in an object. It is a scalar quantity, typically measured in kilograms (kg), grams (g), or milligrams (mg).

Example:

An iron bar with a mass of 2 kg contains a specific number of iron atoms and molecules, which can be accurately measured using an electronic balance.

Analogy: 

Imagine you’re a chef preparing a complex recipe. Each ingredient you add, whether it’s flour, sugar, or spices, contributes to the total amount used in the dish. Just as measuring cups and scales meticulously quantifies each ingredient’s contribution to the recipe’s overall volume.

Measuring instruments in science count particles (atoms and molecules) to determine the mass of an object without changing it. Just as the precise balance of ingredients determines the taste and texture of your culinary creation, the precise measurement of mass is essential for understanding the fundamental composition of matter and its behaviour in various scientific experiments and applications.

Weight

Definition:

Weight is the force exerted by gravity on an object, which varies depending on its position and the gravitational field in which it is located.

• The weight of an object is measured in Newton (N), representing the gravitational force acting on it.

• Unlike mass, which remains constant regardless of location or gravitational field, an object’s weight can vary.

• Weight is directly proportional to an object’s mass and the gravitational field strength (g).

Formula for Weight:

W=mg 

Where:

• W is the weight in Newtons (N),

• m is the mass of the object in kilograms (kg),

• g is the gravitational field strength (approximately 9.8 N/kg on Earth).

Example:

Let’s solve an example: Imagine you have a backpack with a mass of 2 kilograms. To find its weight, you would multiply the mass by the acceleration due to gravity on Earth, which is approximately 9.8 N/kg.

Weight= 2 kg × 9.8 N/kg 

 =19.6 N

So, the weight of the backpack is approximately 19.6 Newtons.

• If the mass is given in grams, convert it to kilograms by dividing by 1000 before multiplying by g.