Answer
a. $83.3$ $kg/m^3$
b. $0.81$ $g/cm^3$
Work Step by Step
a. The given mass is $0.0179$ kg, and the given volume is $215 cm^3$. The mass density is therefore $0.0179/215$ $kg/cm^3=0.00008325581395$ $kg/cm^3$. Since this is a small number, we convert to $kg/m^3$ remembering that one cubic centimeter is equal to $1*10^{-6}$ cubic meters. Therefore our final answer is: $0.00008325581395 \frac{kg}{cm^3} *\frac{1 cm^3}{10^{-6} m^3}=83.3kg/m^3$, remembering to round to the proper amount of significant figures.
b. The given mass is $77$ g, and the given volume is $95 cm^3$. The mass density is therefore $77g/95cm^3=0.81$ $g/cm^3$
