Fluids Demonstration: Measure Volume of Irregularly Shaped Object
by Ron Kurtus (revised 3 May 2007)
Suppose you want to show or demonstrate how to measure the volume of an irregularly shaped object. While you can easily measure the volume of a rectangular object by measuring the lengths of the sides, that technique does not work for an irregularly shaped object.
The solution to this problem is based on the fact that volume is the space an object takes up. If the object is immersed in water, it will displace water equal to the volume of the object. The problem then is to measure the water displaced by the object. A clever way of doing that is to place the object in a bucket that is filled to the top. Then you collect the displaced water that overflows from the bucket.
You can easily measure the volume of the displaced water to find the volume of the object. You can verify the method works by trying it with an object of known volume. A drawback of this method is when the object is bigger than any available container. A problem with this method is if the object is bigger than any available container.
You can easily measure the volume of a rectangular object by measuring the lengths of the sides. The volume (V) of a box is its length (L) times width (W) times height (H) or V = L*W* H.
But suppose you had an object that had an irregular shape. How would you measure its volume? One way would be to immerse the object in a full container of water and measuring the volume of the replaced water.
Measuring the volume of irregularly shaped objects by immersion can be an idea for a science project in the area of physical science or physics. The biggest problem is in verifying that your results are correct. You could establish an empirical rule using known volumes before using the method on unknown volumes.