Density

-The mass density or density of a material is defined as its mass per unit volume.

-We can use these formulas to calculate the density, mass and the volume.

 Density=mass/volume, Mass=density x volume, Volume =mass/density

-possible units =g/mL, g/L, g/cm², kg/L etc.

-1cm³=1mL

-Density of water=1.0g/mL

Dobject > Dliquid  sink

Dobject < Dliquid  float

       














water density

Temp(°c)	Density(kg/m³)
100	958.4
80	971.8
60	983.2
40	992.2
30	995.6502
25	997.0479
22	997.7735
20	998.2071
15	999.1026
10	999.7026
4	999.9720
0	999.8395
-10	998.117
-20	993.547
-30	983.854

-Density problem

1. What is the density of a piece of wood that has a mass of 25.0 grams and a            volume of 29.4 cm³?

Answer: D=25.0g/29.4cm³=0.850 g/cm³

2. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? Would the piece of wood float in water?  (Volume = L x W x H)

Answer: V=3*6*4=72cm³

                D=80.0g/72cm³=1.1 g/cm³; No, it would not float on water

3. I threw a plastic ball in the pool for my dog to fetch. The mass of the ball was 125 grams. What must the volume be to have a density of 0.500 g/mL.

Answer: V=125g/0.500g/mL=2.50 x 10² mL  (250.mL)