Mass is the amount of matter contained in a body. Mass of the body is the constant quantity and does not change with the change of position or location. Weight is the force exerted by a body when it is in a gravitational field. Weight of the body is the variable quantity and changes with the change in position and location due to the acceleration of the gravity acting on it.

Mass is a constant for each object, meaning that the mass won't change unless the object changes. It is an abstract property of the body invariant of the support and defining what acceleration the body gets when being affected by a force. On the other hand Weight changes due to the gravity ; any object's weight is the force pulling it down to the ground.

Newton's law:


Where F is the force , M is the mass and A is the acceleration (the gravity in case of weight). So W=MG, where W is the weight , M is the mass and G is the gravity . So if you apply a force of 1 Newton to a mass of 1kg it will accelerate at 1m/s2. This is true whether the object is floating in space or in a gravity field. This is why weightlessness is possible inside an airplane in freefall (or a space ship rotating an orbit) both experience the same acceleration and so both move with the same speed and so the body exerts zero force onto its support and so it becomes weightless .


  1. Independent of Gravity.
  2. Can never be zero.
  3. Scalar and base quantity.
  4. Ordinary balance is used in measurement.
  5. Measured in grams and kilograms.
  6. Resists motion.


  1. Dependant of Gravity.
  2. When no gravity acts upon the body, it can be zero.
  3. Vector and derived quantity.
  4. Measured using a spring balance.
  5. Expressed in Newton (N).
  6. Produce motion.
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