Density: Measuring Volume

Density: Measuring Volume WALT: Calculate volume of regular and irregular shaped objects I must be able to calculate volume of a regular shaped object I should be able to calculate the volume of irregular shaped objects I could conclude what makes things float or sink

Which is heavier – a kilo of feathers or a kilo of lead?

Density Density is the amount of a substance that is packed into a certain volume. The density of an object can change. Can you think of a situation? - Expansion …… a hot object expands because its particles get further apart – its density will therefore change.

To calculate the density of an object, we need to know 2 things about the object: The volume The mass

Or using the formula triangle; M D x V g/cm3 g Density = mass volume Or using the formula triangle; M D x V cm3

Today we will look at how to calculate the volume of objects Next lesson we will then use that information to calculate the density of objects

There are 2 ways to calculate the volume of an object depending on their shape: 1) Regular shaped objects 2) Irregular Shaped objects

1. Volume of regular shapes volume = length x width x height You each have a square block on your table (or use a regular shaped rubber). Measure its volume. height width length

2. Volume of irregular shapes Difference in level gives the volume of the shape So, let’s say you have a measuring cylinder and it has 500ml of water in. You drop in a key and the cylinder reading goes up to 550ml. What is the volume of your key?

You could also use a displacement can volume of object

The unit of density is always in g/cm3 or kg/m3

Now use the equipment at the back to measure the volume of 3 regular shaped objects and 3 irregular shaped objects (you can use your own things e.g. irregular shaped rubbers etc) Use a displacement can for one irregular shaped object

When you have finished, write or draw a cartoon “Dummy’s Guide” to measuring volume.