# Lesson Worksheet: Calculating Density Physics • 9th Grade

In this worksheet, we will practice using the formula ρ = M/V to calculate the densities of different materials and objects.

**Q1: **

Two spheres have the same mass, but the second sphere has a volume half as big as the first. How much greater is the density of the second sphere than that of the first sphere?

**Q2: **

A scientist has three cubes of different materials. Each cube has a volume of 125 cm^{3}. She weighs each cube to find its mass, and her results are recorded in the table shown. Which material has the highest density?

Material | Volume (cm^{3}) | Mass (kg) |
---|---|---|

Aluminum | 125 | 0.339 |

Copper | 125 | 1.12 |

Cobalt | 125 | 1.09 |

- AAluminum
- BCopper
- CCobalt

**Q3: **

A small cube of iron has sides with length 0.15 m. If the mass of the cube is 26.6 kg, what is its density? Give your answer to the nearest kilogram per cubic metre.

**Q4: **

A cube has a mass of 30 kg. If the
volume of the cube is 0.02 m^{3}, what is
its density?

**Q5: **

Gold can be hammered into very thin sheets. If a thin sheet of gold is 30 cm
wide and 40 cm
long and has a mass of 9.4 g, find the thickness of the sheet.
Use a value of 19,320 kg/m^{3} for the density of gold.
Give your answer in millimeters to four decimal places.

**Q6: **

It is worked out that a solid gold crown has a volume of 150 cm^{3}.
Find the mass of the gold crown, using a value of 19,300 kg/m^{3}
for the density of gold. Give your answer to one decimal place.

**Q7: **

A barrel of crude oil has a volume of 0.159 m^{3}. Find the mass of the oil contained by the barrel, using a value of 900 kg/m^{3} for the density of oil. Give your answer to the nearest kilogram.

**Q8: **

Find the volume of a 54 kg block of aluminum. Use a value of 2,700 kg/m^{3} for the density of aluminum.

**Q9: **

A bowling ball has a mass of 5.5 kg. The bowling ball is a sphere with a radius of 7 cm. What is the density of the bowling ball? Give your answer to the nearest kilogram per cubic meter.

**Q10: **

A brick has a mass of 3.5 kg. It is a rectangular prism with side lengths of 23 cm, 11 cm, and 7 cm. What is the density of the brick? Give your answer to the nearest kilogram per cubic meter.