Density – problems and solutions

1. The volume of an object is 8 cm3 and mass of an object is 84 gram. What is the density of the object?

Known :

Volume (V) = 8 cm3

Mass (m) = 84 gram

Wanted : density (ρ)

Solution :

ρ = m / V = 84 gram / 8 cm3 = 10.5 gram/cm3

2. Volume of an block is 5 cm3. If the density of the block is 250 g/cm3, what is the mass of the block ?

Known :

Volume (V) = 5 cm3

Density (ρ) = 250 g/cm3

Wanted : Mass of the block

Solution :

ρ = m / V

ρ = density, V = volume, m = mass

Mass of block :

m = ρ V = (250 g/cm3)(5 cm3) = 1250 gram

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3. Volume of water is 35 cm3 and mass of water is 60 gram, what is the density of the water.

Known :

Volume of water (V) = 35 cm3

Mass of water (m) = 60 gram

Wanted: density (ρ)

Solution :

density :

ρ = m / V = 60/35 = 1.71 gram/cm3

4. Mass of an metal is 120 gram and volume of an metal is 60 cm3. What is the density of the metal?

Known :

Mass (m) = 120 gram

Volume (V) = 60 cm3

Wanted : density

Solution :

ρ = m / V

ρ = 120 gram / 60 cm3

ρ = 2 gram/cm3

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5.

Density – problems and solutions 1

Based on the table, an object with the same density is…

Solution :

Formula of density :

ρ = m / V

ρ = density, m = mass, V = volume

Density – problems and solutions 2

6. Based on the figure below, if the mass of an object is 300 gram, what is the density of the object.

Known :Density – problems and solutions 3

Mass (m) = 300 gram

Volume (V) = volume of spilled water = 20 cm3

Wanted : density

Solution :

ρ = m / V = 300 gram / 20 cm3 = 15 gram/cm3

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7. Mass of object is 316 gram, placed in a container as shown in figure. What is the density of the object.

Known :Density – problems and solutions 4

Mass (m) = 316 gram

Volume (V) = volume of spilled water = 40 ml

Wanted : density

Solution :

Mass = 316 gram = 316/1000 kg = 0.316 kg

Volume = 40 ml = 40/1000 liters = 4/100 liters = 0.04 liters

1 liter = 1 dm3 = 1/1000 m3 = 0.001 m3

0.04 liters = (0.04)(0.001) m3 = 0.00004 m3

Density :

ρ = m / V = 0.316 kg / 0.00004 m3 = 316 kg / 0.04 m3 = 7900 kg/m3

8.

Density – problems and solutions 5The density of stone based on the image is…

Known :

Mass (m) = 100 gram + 20 gram = 120 gram = 120 / 1000 kilogram = 0.120 kilogram

Volume (V) = 80 ml – 60 ml = 20 ml = 20 / 1000 liters = 2/100 liters = 0.02 liters

1 liter = 1 dm3 = 1/1000 m3 = 0.001 m3

0.02 liters = 0.02 x 0.001 m3 = 0.00002 m3

Wanted : density

Solution :

Density :

ρ = m / V = 0.120 kg / 0.00002 m3 = 120 kg / 0.02 m3 = 6000 kg/m3