PDF chapter test TRY NOW

1. Define the density of objects.
 
Density is defined as the of the substance contained in a unit .
 
The formula for density (\(D\)) is given as
 
 
The SI unit of density is and the CGS unit is  \(g/ cm^3\).
 
2. What is one light year?
 
The covered by the light travelling at a speed of  \(\times{10^8}\) \(m\) in for a year gives one light year.
 
The value of one light-year can be calculated by  of light and the total by the light in one year.