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Equipment

Density Can
AKA: Eureka Can

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Fig 1: Density or Eureka can
Fig 1
Fig 2

Summary

You can measure the volume of a solid object by placing it in this can of water. The amount of water it displaces is equal to that of its volume.

Operation

These cans can be purchased through most lab suppliers. Measuring cylinders can be used instead of these cans to achieve the same effect.

The can is filled as high as possible with water and an object inserted slowly into it. As the object fits into the can, the water it displaces pours out of the spout. This displaced water can then be measured and will be the same as the volume of the object. For example a 10 cm³ cube will displace 10cm³ of water.

The density of some common objects are listed below for comparison:

Substance Density (g/cm³)
Air 0.0013
Feathers 0.0025
Oak 0.6-0.9
Ice 0.92
Water 1.0
Bricks 1.84
Aluminium 2.70
Steel 7.80
Silver 10.50
Gold 19.30

The density of a material can be worked out using this equation:

p=m/V

where p is the density of a material, m is mass and V the volume.

With the density can and an accurate balance, we can work out the volume of a substance and also the mass. From this we can, using the above equation, work out the density of the substance.

Safety

 CautionThe contents of this page are for information only. Please refer to CLEAPSS or ASE safety advice and/or publications before undertaking any preparation, practical experiment or using any equipment featured on this site or any other.

Notes

Archemedes apparently jumped into a bathtub thousands of years ago and realised that the level of bathwater rose accordingly. He ran through the streets naked shouting 'Eureka! Eureka!' (meaning I’ve found it!) What he had discovered was the idea of fluid displacement. Knowing this principle led designers to create massive ships that displace enough water to allow them to float.