1. Density (2)

2. Density (2)
WALT: Calculate density of regular and irregular shaped objects I must be able to calculate density using the equation and include correct units I should be able to calculate the volume and density of irregular shaped objects I could conclude what makes things float or sink

3. Last lesson, we learnt
That to calculate volume of a regular shaped object, you ………
To calculate the volume of an irregular shaped object, you ………………….. or ……………..
That density is …………….
That the equation for density is ………………..

4. Density
Density is the amount of a substance that is packed into a certain volume.
So, which is more dense – a liquid or a solid or a gas?

5. 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

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

7. Yesterday, we learnt how to calculate volume
How would we calculate the mass of an object?

8. Mass of liquids Mass of liquid Mass of cylinder
Mass of liquid and cylinder

9. So, now you know how to calculate the volume of something and the mass of something, you can calculate its density.
Density = mass / volume

10. Density = mass / volume
If a piece of wood has a mass of 10g and a volume of 2cm3, what is its density?

11. Density = mass / volume
If an object has a mass of 10kg and a density of 100kg/m3, what is its volume?
If an object has a volume of 6cm3 and a density of 18g/cm3, what is its mass?

12. Using the same methods as yesterday to measure volume, measure the density of 2 regular shaped objects and 2 irregular shaped objects.
What might your table(s) look like so that you can record this info?

13. Now it´s your turn
Follow the instructions on the worksheet to calculate the volumes and densities of 3 regular and 3 irregular shaped objects When you have finished, do question 4 on page 148. You will need to re-arrange the equation. How might we do this?

14. Prep Carry out the worksheet questions on density
Make a quick rap/poem/song to help us remember the density equation

15. Plenary
If a salt solution has a density of 1.2g/cm3, what volume of the solution would have a mass of 840g.