gDensity is a property of matter that relates the mass to its volume, we can calculate it with the following equation:
[tex]\rho=\frac{M}{V}[/tex]Where,
[tex]\begin{gathered} \rho\text{ is the density of the substance} \\ M\text{ is the mass of the substance}=19.8g \\ \text{V is the volumen of the substance} \end{gathered}[/tex]Now, we have to calculate the volume of the solid. We do that by calculating the volume of a cylinder. The equation is:
[tex]V=\pi\times r^2\times h[/tex]Where,
Pi=3.14
r= Radius = Diameter/2 = 9.5mm/2=4.75mm =0.475cm
h = Length = 20.8mm = 2.08cm
We replace the values:
[tex]\begin{gathered} V=\pi\times(0.475\operatorname{cm})^2\times2.08\operatorname{cm} \\ V=1.47\operatorname{cm}^3 \end{gathered}[/tex]Now, we replace the known values in the density equation:
[tex]\rho=\frac{M}{V}=\frac{19.8g}{1.47\operatorname{cm}^3}=13.4\frac{g}{cm^3}[/tex]So, the density of a cylindrical solid with a mass of 19.8g is 13.4g