Difference Between Mass And Weight

We often hear the terms weight and mass of objects. Though they are related words, they do not mean the same thing. The definition of weight and mass of objects as seen in physics boos will give you different characteristics of objects.

Comparing weight and mass

There is a simple way to understand the difference between weight and mass. Weight can be explained as the force with which the gravity pulls an object. Your weight will not be the same in all planets. In moon, you will weigh far lesser than how much you weigh on the earth. However, in earth and in the moon, your mass will remain the same. Because, mass is the amount of matter contained in a given object.

Difference between weight and mass


What is mass?

Mass can be explained as the amount of matter a body contains. This is a constant quantity and will not change when the body changes its position or location.

What is weight?

Weight is the force that the body exerts when it is subjected to a gravitational field. The weight of a body depends on the extent of the gravitational pull. Weight of a body is certainly a variable quantity that will change when the object changes its location and position on account of the gravity acting on it. They are used in different places and in different times.

Understanding mass and weight in detail

  • Mass is constant for every object. Unless the objects changes, the mass will not change. On the other hand, the weight of an object is subjected to change due to gravity. The weight of an object is the force pulling it to the ground. Mass is measured in kilograms.
  • Mass is the inertial mass of the object. It is never the same as weight. Weight depends on the gravitational field. We all know that the acceleration of an object on the earth’s surface due to gravity is 9.8m/S2. For example, if the mass of an object is 5 kilograms on the earth, its weight would be 9.8 X 5 = 49 N. A weighing machine reports the weight of an object and not its mass. To calculate the mass, you will have to divide the weight of the object by the acceleration due to gravity at that given point.
  • The weighing scale measures the force a given body exerts on the weighing scale. It does not measure the mass of the body. If you stand on a weighing scale during free fall, it will only register zero since you are never exerting any additional force on the weighing scale.
  • Mass is the abstract property of an object. It is independent of the acceleration it is likely to get while it is subjected to a force. Weightlessness is possible inside an airplane during free fall or spaceship rotating in its orbit. Since both the object and the airplane or spacecraft experience the same acceleration and are moving in the same speed, the body exerts zero force onto its support and hence it becomes weightless.