Mass Vs Weight

Mass	Weight
Mass is the quantity of matter in a body.	Weight is the force with which a body is attracted towards the center of the earth.
Mass is a scalar quantity.	Weight is a vector quantity.
The mass of an object is constant on Earth and even in space.	The weight of an object can vary from place to place and becomes zero at the center of the earth. It is also zero in places that are far away from earth.
m = F/a is the mass of a moving body.	W = mg, is the weight of a body.
An ordinary weighing balance can help you weigh mass.	Spring balance helps measure the weight of an object.
The unit of mass in the S.I system is Kilogram (kg).	The unit of weight in S.I system is Newton (N)
1. Mass is an intrinsic property of a body. 2. It is independent of any external factor.	1. Weight of an object depends on the mass of an object that is attracting it. 2. Weight is also dependent on the force with which it is attracted. It in turn depends on the distance between the two objects.

How to Calculate Mass and Weight of an Unknown Object?

You can calculate mass of unknown object by balancing it with a known amount of mass. You need to balance the unknown object on a weighing scale with an object of known mass like 1 kg, 2 kg, 3 kg, etc. till both the sides are balanced. Then add up the numbers of the known side of mass and calculate the unknown mass. When masses are equal on both sides, then the balance of the effect of gravity will cancel out for both, in other words, the weight cancels out. Thus, unknown mass can be calculated with the help of the known mass of the object at the other side of the balance. Weight, on the other hand, can be calculated using a scale that measures the pull on the mass that is exerted by the Earth's gravity.