A student put two identical nails, each with a mass of 12g, into a graduated cylinder containing 120 cm³ of water. After adding the two nails the water level rose and the reading on the cylinder was 128 cm³. What was the density of the nails?
8 g/cm³
3 g/cm³
6 g/cm³
10 g/cm³
The increase in volume of the water is equal to the volume of the nails.
Volume of the water displaced = 128 cm³ - 120 cm³ = 8 cm³
Since there are two nails, the volume of each nail is 8 cm³ ÷ 2 = 4 cm³
The mass of each nail is 12g.
Density = Mass ÷ Volume = 12g ÷ 4 cm³ = 3 g/cm³
Therefore, the density of the nails is 3 g/cm³.