Unit & Dimensions

Unit & Dimensions

Important Practical Units

Length

• Astronomical Unit (au): Distance Between the centre of Earth and the centre of the Sun (1 au = 1.5 x 10¹¹ m)
• Light Year (ly): Distance travelled by light in vacuum in one year.
• 1 Angstrom = 10^-10 m

mass & weight

• The largest practical unit of mass is Chandrasekhar limit (CSL).
• Atomic or nuclear masses are made in terms of a unit called amu (atomic mass unit).