Question

question 22: an object has a density of 1.4 g/cm³. it is slowly lowered into a graduated cylinder whose water level was 65 ml. when the object is completely submerged the water level rises to 90 ml. what is the mass of the object? 18 g 21 g 35 g 15 g

Explanation:

Step1: Find volume of the object

The volume of the object is equal to the volume of water displaced. The initial water - level is 65 mL and the final water - level is 90 mL. So, $V=(90 - 65)\text{mL}=25\text{mL}$. Since $1\text{mL} = 1\text{cm}^3$, $V = 25\text{cm}^3$.

Step2: Use density formula to find mass

The density formula is $
ho=\frac{m}{V}$, where $
ho$ is density, $m$ is mass and $V$ is volume. We know that $
ho = 1.4\text{g/cm}^3$ and $V=25\text{cm}^3$. Rearranging the formula for $m$ gives $m=
ho\times V$. Substituting the values, we get $m = 1.4\text{g/cm}^3\times25\text{cm}^3$.
$m=35\text{g}$

Answer:

35 g