In general language, we use mass and weight interchangeably
However both are not same in scientific language
Difference between Mass and Weight
Mass | Weight |
It is quantity of matter contained in a body | It is a force by which a body is attracted towards center of earth |
It is measured in kilogram (SI Unit of mass is kg) | It is measured in Newton (SI Unit of weight is N) |
Mass of a body remains constant | Weight of an object changes as per acceleration due to gravity |
Mass of a body is same on earth and moon | Weight of body on moon is 1/6 of mass of body on earth |
Mass of body can never be 0 | In case acceleration due to gravity g is 0, weight can be 0 (example in space,weight of body is 0) |
Mass is a scalar quantity,it only has magnitude | Weight is a vector quantity, it has magnitude as well as direction |
How is Weight of body calculated?
We know that
Force = Mass x Acceleration
Since Weight is also kind of a force by which a body is attracted towards center of earth,we can say that
Weight = Mass x Acceleration
In Place of Acceleration,we can use Acceleration due to gravity
Weight = Mass x Acceleration due to gravity
W = M x g
What is weight of body of mass 1 kg?
We know that
W = m x g
In this case m = 1 kg, g = 9.8 m/s2
W = 1 x 9.8
W = 9.8
W = 9.8 Newton (kg m/s2)
What is weight of body on moon
Mass of earth is 100 times that of moon
Radius of earth is 4 times that of moon
If we put these values in Gravitational Force formula,
We find that
Weight of a body on moon is 1/6th of weight of body on earth
Let's Prove it
To check exact proof, check Derivation
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