Question

an object with a mass of 7.9g raises the level of water in a graduated cylinder from 24.6 ml to 28.8 ml. what is the density of the object? round to appropriate sigfigs. (1 point) 1.88 g/ml 0.532 g/ml 1.9 g/ml 0.53 g/ml

Explanation:

Step1: Calculate the volume of the object

The volume \( V \) of the object is equal to the change in water level.
\( V=V_{final}-V_{initial}\)
\( V = 28.8\space mL-24.6\space mL=4.2\space mL\)

Step2: Calculate the density of the object

The formula for density \(
ho\) is \(
ho=\frac{m}{V}\), where \( m = 7.9\space g\) and \( V = 4.2\space mL\)
\(
ho=\frac{7.9\space g}{4.2\space mL}\approx1.88\space g/mL\)
But considering significant figures:

• The mass \( 7.9\) has 2 significant figures.
• The volume \( 4.2\) has 2 significant figures.

When dividing, the result should have the same number of significant figures as the least - precise measurement. So \(
ho=\frac{7.9}{4.2}\approx1.9\space g/mL\) (rounded to 2 significant figures)

Answer:

1.9 g/mL