Question

A 2.98 gram rectangular object has measurements of 21.1 mm, 14.2 mm, and 12.1 mm. What is the object’s density in units of g/mL? Use significant figures. Do not enter “g/mL” as part of your answer. Do not use scientific notation.

Answer 1

To find an object's density in g/mL, divide its mass in grams by its volume in cubic centimeters. With the mass given as 2.98 g and the volume calculated as 3.620322 cm³, the density is 0.823294 g/cm³, rounded to 0.823 g/cm³ to match the significant figures of the given measurements.

Step-by-step explanation:

To calculate the density of an object, we divide its mass by its volume. The mass of the object is given as 2.98 grams. To find the volume, we multiply its length, width, and height: 21.1 mm × 14.2 mm × 12.1 mm. Converting mm to cm, since there are 10 mm in a cm, the volume in cubic centimeters is 2.11 cm × 1.42 cm × 1.21 cm = 3.620322 cm³.

The raw density calculation yields 2.98 g / 3.620322 cm³ = 0.823294 g/cm³. However, since the volume measurement has only three significant figures, we must round the final answer to match. Thus, the density would be rounded to 0.823 g/cm³, with three significant figures, to match the least number of significant figures in the given measurements.

Answer 2

density = 0.822 g/mL

Step-by-step explanation:

We calculate the density knowing the flowing formula:

density = mass / volume

mass = 2.98 grams

volume = 21.1 × 14.2 × 12.1 = 3625 mm³ = 3.625 cm³ = 3.625 mL

density = 2.98 / 3.625 = 0.822 g/mL