Question

1. a plastic ball with a volume of 19.7 cm³ has a mass of 15.8 g. would this ball sink or float in a container of gasoline?

Explanation:

Step1: Calculate the density of the plastic ball

Density formula is $
ho=\frac{m}{V}$, where $m = 15.8\ g$ and $V=19.7\ cm^{3}$. So $
ho_{ball}=\frac{15.8\ g}{19.7\ cm^{3}}\approx 0.802\ g/cm^{3}$.

Step2: Recall the density of gasoline

The density of gasoline is approximately $
ho_{gasoline}=0.70 - 0.78\ g/cm^{3}$.

Step3: Compare the densities

Since $
ho_{ball}\approx 0.802\ g/cm^{3}$ and $
ho_{gasoline}=0.70 - 0.78\ g/cm^{3}$, and $
ho_{ball}>
ho_{gasoline}$.

Answer:

The ball would sink.