Question

1 when an object is submerged in 50cm³ of water, the level rises to 65cm³. the mass of the object is 30g. what is its density? a 450\frac{g}{cm³} b 45\frac{g}{cm³} c 15\frac{g}{cm³}

Explanation:

Step1: Find the volume of the object

The volume of the object is equal to the increase in the volume of water when the object is submerged. So $V = 65\mathrm{cm}^3 - 50\mathrm{cm}^3=15\mathrm{cm}^3$.

Step2: Calculate the density

The density formula is $
ho=\frac{m}{V}$, where $m = 30g$ and $V = 15\mathrm{cm}^3$. Then $
ho=\frac{30g}{15\mathrm{cm}^3}=2g/\mathrm{cm}^3$. But let's check the options based on the steps we took conceptually. The volume of the object is $15\mathrm{cm}^3$ and mass is $30g$. The density $
ho=\frac{m}{V}$. If we made a mistake in reading the options concept - wise, we know that density is mass per unit volume.

Answer:

None of the given options (A. $450\frac{g}{cm^3}$, B. $45\frac{g}{cm^3}$, C. $15\frac{g}{cm^3}$) are correct. The correct density is $2\frac{g}{cm^3}$.