Question

The density of material in the CGS system of units is $4gc{m}^{-3}$ . In a system of units in which unit of length is $10cm$ and the unit of mass is $100g$ , the value of density of the material will be

• A. $0.4$
• B. $40$
• C. $400$
• D. $0.04$

Answer 1

Answer: (B)

In the CGS system,
$d=4gc{m}^{-3}$
The unit of mass is $100g$ and unit of length is $10cm$ , so
density $=\frac{4(\frac{100g}{100})}{(\frac{10}{10}cm{)}^3}$
$=\frac{(\frac{4}{100})}{(\frac{1}{10}{)}^3}\frac{(100g)}{(10cm{)}^3}$
$=\frac{4}{100}\times (10{)}^3\frac{100g}{(10cm{)}^3}$
$=40$ units