1. The mass of a sample of material can easily be calculated if we are given the density and the volume.

2. In this example, we’re given that iron has a density of 7.8 grams per cubic centimeter, and we’re asked to find the mass of a 35 cubic centimeter sample of iron. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron.

3. In all problems having to do with density, we can start with the density formula, density equals mass divided by volume. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume The density formula × volume ×

4. In this problem, we’re asked for the mass and we’re given the density and the volume. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume The density formula × volume ×

5. So we need to rearrange this equation to solve for mass. In other words we need to get the word mass on one side of the equation, all by itself. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume × × Solve this Equation for Mass

6. To get mass by itself on the right side of the equation, we need to cancel out volume from the denominator here Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume × × We need to cancel out volume from here

7. We can do something to an equation as long as we do the same thing to both sides, so we’ll multiply both sides of the equation by volume (click) like this Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume × ×

8. On the right side we have volume both in the numerator and the denominator, so we can (click) cancel out volume Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume × × These can be cancelled

9. So this will leave us with only mass on the right side. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = mass volume × ×

10. Now we’ll move mass to the left side (click) and volume and density to the right side. This doesn’t change the equation Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. = densityvolume × mass

11. density To get the most familiar form of this equation, we’ll switch position of volume and density (click). Again, this doesn’t change the equation. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. = volume × mass

12. Now that we have the equation for mass, Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass

13. we can substitute values for density and volume into this equation and calculate the mass. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass

14. We substitute 7.8 grams per cubic centimeter for the density because that was given in the question. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass

15. And we substitute 35 cubic centimeters in for the volume, as that is also given Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass

16. We don’t need to change the unit of volume. It is in cubic centimeters and the density has cubic centimeters in the denominator of its unit. So the unit cubic centimeters (click) can be cancelled out. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass This unit will cancel

17. Multiplying 7.8 grams per cubic centimeter by 35 cubic centimeters, Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass

18. and cancelling out cubic centimeters, Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass

19. Gives us a mass of 273 grams. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass 273 gmass =

20. The whole calculation can be summarized here. Mass is equal to density times volume Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass 273 gmass =

21. Which is 7.8 grams per cubic centimeter times 35 cubic centimeters Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass 273 gmass =

22. Which comes out to 273 grams. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass 273 gmass =

23. So we can state the final answer as, the mass of a 35 cubic centimeter sample of iron is 273 grams. Iron has a density of 7.8 g/cm 3. Calculate the mass of a 35 cm 3 sample of iron. density = volume × mass 7.8 g/cm 3 = 35 cm 3 × mass 273 gmass = The mass of a 35 cm 3 sample of iron is 273 g