1. Archimedes Dilemma ???????
A long time ago, in the 3rd century B.C. there was a king in Syracuse (modern day Italy) who wanted a pure gold crown. The royal goldsmith made him a crown, but the king thought that maybe the goldsmith had cheated him by mixing the gold and silver to make a silver/gold alloy and keeping some of the gold for himself. The king went to Archimedes, a famous scientist, to solve the problem. What should Archimedes do?
Answer will be given at the end of class……..!

2. Density

3. A physical property of matter.
Density
A physical property of matter.
DEF: The amount of matter (mass) packed into a given space (volume).

4. Density
More dense
Less dense
Ex: brass
Ex: wood

5. More dense = SINK
Less dense = FLOAT
Oil
Water

6. Answer: Oil is less dense than water so it floats.
BP Gulf Oil Spill: If the oil leaked from a pipe near the bottom of the ocean floor, how did it end up at the surface?
Answer: Oil is less dense than water so it floats.
Source:

7. DENSITY = MASS Volume Volume = 10cm x 10 cm x 10 cm = 1,000 cm3
Mass = 2,000 g
Density = 2,000 g ,000 cm3
= 2 g/cm3

8. Another Example:
V = 10 mL
M = 30 g
D = M V
D = 30g 10mL
D = 3 g/mL

9. Archimedes Dilemma ???????
At first, Archimedes did not know how to test the crown. That is until one day he was taking a bath and noticed how the water went up and down as he entered the baths. Archimedes jumped out of the tub and ran down the streets screaming “Eureka, Eureka!” or “I’ve got it!” He discovered that by placing the crown in the water he could observe the volume of water that the crown displaced. Since he could already measure the mass of the crown, he could find the density of the crown and compare it to the density of gold and silver. Legend has it that the crown displaced more water than gold, but less than silver, proving that the crown was not pure gold.