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1. Define density and show the formula for calculating density.

**Density is a measure of the amount of mass (weight) that exists in a given volume. Density is basically how much "stuff" is smashed into a particular area **

𝑴𝒂𝒔𝒔

**Formula: Density = **

𝑽𝒐𝒍𝒖𝒎𝒆

** or D = **

𝑴

𝑽

2. Why does changing the shape of an object have no effect on the density of that object?

**It's not affected by changes in the amount of the material. You can add, remove, or reshape the material all you want, and its density will be unaffected. If the material is **

***not* constant (like if you squished bread), then changing shape may change the density. **

3. Aluminum is used to make airplanes. Cast iron is used to make weightlifting equipment. Explain why the densities of these metals make them useful for these purposes?

** Aluminum is less dense, making it one of the ideal metals for airplanes, as it weighs less. Iron is a more dense metal, which makes for a better weight because it requires less volume for an effective bar bell. **

4. Calculate the densities of the following objects.

**Remember to include the proper units. **

**Object A: Object B:**

length = 6cm width = 3cm height = 1cm mass = 36g length = 10cm width = 5cm height = 2cm mass = 300g

**Object C below**

V

V initial final

(silly putty)

= 25ml

= 29ml

**: see **

mass of silly putty = 8g

Volume = l x w x h

= 6 x 3 x 1

= 18 cm

3 𝑚𝑎𝑠𝑠

Density = 𝑣𝑜𝑙𝑢𝑚𝑒

36𝑔

=

18𝑐𝑚

3

= 2 g/cm

3

**The liquids that weigh more (have a higher density) will sink below the liquids that weigh less (have a lower density) **

5. Which of the following materials will float on water (density 1 g/cm

3

)? corn oil glycerine

= 0.93 g/cm

3

= 1.26 g/cm

3 corn syrup = 1.38 g/cm

3 wood steel rubber ice

= 0.85 g/cm

3

= 7.81 g/cm

3

= 1.34 g/cm

3

= 0.92 g/cm

3

6

. Assuming the materials don’t mix, show how the materials would "stack up" in the container:

Density = Mass

Volume

**Extra Problems: **

Density x Volume = Mass Volume = Mass

Density

1. A block of wood measures 3cm x 6cm x 2cm and has a mass of 10g. Calculate the density of this object.

2. Calculate the mass of an object that has a volume of 12 cm

3

and a density of 3.2 g/cm

3

.

3. Calculate the volume of an object that has a mass of 5.6 g and a density of 3.1 g/cm

3

.

4. Calculate the density of an object that has a mass of 44.5g and displaces 6.2mL volume of water.

5. The density of a solid is 0.89 g/cm

3

. If the mass of the object is 105g, determine the volume.

6. The volume change in a graduated cylinder is 13mL, when you place an irregular shaped solid inside. The density of the solid is 1.25g/mL. What is the mass of the solid?

7. A sample of platinum occupying a volume of 6.0cm

3

has a mass of 1.28g. Calculate the density of platinum.

8. You have a graduated cylinder with 20mL of water in it. You add 250g of lead weights, and the volume of water rises to 42mL. What is the density of the lead?