Difference Between Mass and Weight

Mass and weight are two different physical quantities which are often confused. Mass refers to the amount of matter in an object, while weight is the gravitational force acting on it. While mass remains constant, weight varies depending on the gravitational field strength. In this article, we will learn the differences between mass and weight in detail.

What is Mass?

Mass refers to the amount of matter contained within an object. It is a fundamental property of all matter and is measured in kilograms (kg) or grams (g). Mass is a scalar quantity, meaning it has magnitude but no direction. It is an intrinsic property of an object, which means it does not change regardless of its location in the universe.

The formula to calculate mass is:

Mass = Force/ Acceleration

where,

• Mass is the amount of matter in an object,
• Force is the applied force on the object, and
• Acceleration is the rate of change of velocity of the object.

What is Weight?

Weight is the gravitational force acting on an object due to its mass. It is a vector quantity, having both magnitude and direction. It is measured in units such as newtons (N) or pounds (lbs). Unlike mass, weight can vary depending on the gravitational field strength of the celestial body.

It is calculated using the formula:

Weight = mass × gravitational acceleration

where the gravitational acceleration is approximately 9.8 m/s² on Earth.

This means that weight depends on both the mass of the object and the strength of the gravitational field it is in.

Weight is what we feel when we stand on a scale. It is the force exerted by the ground on our bodies due to Earth’s gravity. When we travel to different planets or celestial bodies, our weight would change because the gravitational field strength varies.

Difference Between Mass and Weight

Mass is often confused with weight, but they are not the same. Here are some fundamental differences between Mass and Weight :

Difference	Mass	Weight
Definition	Mass is the amount of matter in an object.	Weight is the force exerted by gravity on an object.
SI Unit	Kilogram (kg)	Newton (N)
Measurement	Mass remains constant regardless of location.	Weight varies depending on the gravitational field.
Influence of Gravity	Mass is not influenced by gravity.	Weight is directly proportional to the gravitational force acting on an object.
Formula	Mass = (Density) × (Volume)	Weight = (Mass) × (Acceleration due to gravity)
Example	An object with a mass of 5 kg.	An object weighing 50 N on Earth’s surface.
Relationship to Inertia	Mass is directly related to an object’s inertia, determining its resistance to changes in motion.	Weight does not affect an object’s inertia directly, as it is a force rather than an intrinsic property of the object.
Effect of Location	Mass remains the same regardless of the location or environment.	Weight changes with location, as it depends on the gravitational field strength of the location.
Measurement Device	Mass is measured using a balance or scale.	Weight is measured using a spring balance or weighing scale.
Impact on Scale Readings	Mass affects the reading of a scale, determining how much the scale is displaced.	Weight affects the reading of a scale due to the force exerted by gravity, causing a deflection of the scale.

Conclusion

In conclusion, mass measures the amount of matter in an object and remains constant while weight is the gravitational force acting on an object and can vary. While mass is measured in kilograms or grams, weight is measured in newtons or pounds. Mass determines inertia, while weight depends on gravity’s strength. Both mass and weight play important roles in physics, engineering, and everyday life.

FAQs on Difference Between Mass and Weight

What is the fundamental difference between mass and weight?

Mass refers to the amount of matter in an object, while weight is the gravitational force acting on an object.

How do we measure mass and weight differently?

Mass is typically measured in kilograms or grams, while weight is measured in newtons or pounds.

Does mass change with location?

No, mass remains constant regardless of location in the universe.

How does weight vary on different celestial bodies?

Weight varies depending on the gravitational pull of the celestial body; it is different on Earth, the Moon, and other planets.

Why is mass considered a fundamental property?

Mass determines an object’s inertia and is used in various physics equations and laws.

Can you calculate mass and weight differently?

Mass can be calculated by dividing the force acting on an object by its acceleration due to gravity, while weight can be calculated by multiplying an object’s mass by the acceleration due to gravity.

Is it possible for a body to have mass but not weight?

Yes, it is possible for a body to have mass but not weight in a location where there is no gravitational force acting on it, such as in outer space.