
Mass: It is the amount of matter (substance) in a body.

Weight: The downward force equal to product of mass and the gravitational field strength.
W = m g

Differences:
Weight 
Mass 

It is a force. 
It is the amount of matter in a body. 
Measured in N 
Measured in kg 
Vector 
Scalar (,i.e., no direction) 
Changes from place to place 
Constant regardless of location 

Inertia: It is the reluctance of mass to a change in its state of motion.

A truck has more mass and hence more inertia than a car.


Gravitational field strength of Earth is 10 N/kg. This means that the strength of Earth’s gravity is so strong that an object will have a weight of 10 N for every kg of mass that it has.

Unit: N/kg


Measuring instruments:

Spring balance: Measures weight.
Using the formula W=mg, it can have a scale for mass too. The value of ‘g’ is assumed in such a case.

Beam balance: Measures mass by comparing the weight of a mass with the weight of known masses (e.g., discs).


Density: It is the mass per unit volume.
ρ = m / V


SI Unit: kg/m^{3}


Measurement of volume: Volume can be found by:

Displacing a liquid

For regular shaped objects such as a block or cylinder, a formula may be used.


Less dense liquids and gases rise above more dense liquids and gases respectively.
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