Density is a physical property of matter that measures the mass per unit volume of a substance. The formula for density is D=m/V. This property explains why oil floats in water. Just check out your nearest Italian dressing to see this phenomenon.
You may have heard about the recent oil spill in the Gulf of Mexico. Many clean up solutions involve corralling, scraping or burning the oil off the surface of the water. These techniques are possible because of the density of crude oil, it is less dense than sea water. The oil leaks from the well and travels to the surface of the ocean water. Find out what the density of crude oil and sea water are. Build a model of this disaster in your classroom.
Thought Questions:
- What other techniques are they using to contain the oil?
- How does it work?
- What do you think they should try?
- Suggest some techniques that utilize new technologies.
Read about the disaster and watch videos of the clean up here:
http://edition.cnn.com/2010/US/05/07/gulf.oil.spill/?hpt=Sbin
http://www.foxnews.com/story/0,2933,592582,00.html
Another common example for density compares the masses of gold and aluminum. Gold is a very dense substance while aluminum is not. The density of gold is 19.30 g*cm-3 while the density of aluminum is 2.70 g*cm-3. If we were holding a brick of gold in one hand and a brick of aluminum in the other we would discover the gold brick is much heavier. This is because the gold is much denser and has more mass than aluminum. Although both bricks have the same volume the gold is much denser therefore more massive.
Wednesday, May 12, 2010
Word of the Week: Density
