Explain measurement of mass of body.

Explanation

Generally mass of body is measured by common (physical) balance. Large mass in universe (like planet or stars) is based on Newton.s universal law of gravitation
`[ m(Fr^(2))/(GM_(e))]`
To measure very small mass (like atom) mass spectrometer is used. In this instrument radius of the trajectory is proportional to the mass of charged particle moving in uniform electric and magnetic field.