Trapped Oil
Oil, Water, Alcohol and Buoyancy
by Kosta Petridis, Jon Kerby, Stavro Latos 2012
When a substance is placed in a liquid it either sinks or floats. A substance will sink in a liquid if its density is greater than the liquid. A substance will float in a liquid if has a density that is less than the liquid. The oil in this demo gets trapped between the alcohol and water because its density is less than alcohol and greater than the water.
http://www.showmethephysics.com/home/...
Soundtrack - Cambodean Odessy - Creative Commons - http://incompetech.com/m/c/royalty-free/"