Density

Question 1

What is the formula for density?

Answer 1

Density = mass / volume

P = M / V

Question 2

A solid metal cube has a mass of 5kg and side length 0.5m^3.
Calculate the density of the cube.

Answer 2

Density = 5 / 0.5^3
= 5 / 0.125
= 40 kg/m^3

Question 3

A rock has a mass of 0.6kg and a volume of 0.15m^3.
Calculate its density

Answer 3

Density = 0.6 / 0.15
= 4 kg/m^3

Question 4

A cube box has a density of 25 kg/m^3 and a mass of 8kg.
Calculate the length of each side.

Answer 4

25 = 8 / V (m^3)
m^3 = 25 / 8
= \sqrt[3]{\frac{25}{8}}
= small 3 root (25 / 8)
= 1.462008869
= 1.46 (to 2dp)

Question 5

A student wants to find out the density of a rock. Describe an experiment they could perform to determine the density of this rock.

Answer 5

First, fill up a eureka can just up to the spout.
Set up a measuring cylinder to catch any water that comes out of the spout.
Use a balance to record the mass of the rock, and the place the rock into the water.
The volume of the water in the measuring cylinder is the same as the volume of the rock. Record this volume.
Use P = M / V to find the density of the piece of rock.