1. Density: Measuring Volume

2. 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

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

4. 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.

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

6. 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

7. 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

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

9. 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

10. 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?

11. You could also use a displacement can
volume of object

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

13. 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

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