Translations:AY Honors/Oceans/Answer Key/41/en

Experiment:

On a surface that is safe to spill some vegetable oil, fill the baking dish about half to three-quarters full of vegetable oil. (Depending on the exact size of baking dish you are using, this may be about 4 cups of vegetable oil or less.)
Mix the 2 teaspoons of thyme in with the vegetable oil in the baking dish. Stir thoroughly to distribute the flakes of thyme. The flakes of thyme will flow with the liquid, showing the direction and velocity of any fluid flow.
Place the baking dish on top of the two ceramic mugs.
Observe the oil and spice mixture. With no heat (energy) being added to the system, there should be little or no movement of the liquid, once it has settled.
Place a candle underneath the baking dish, directly in the middle. Make sure the mugs still stably support the baking dish.
Light the candle and let the liquid heat up for at least one minute. Your setup should look like the picture below. You can also use a can of Sterno instead of a candle. Sterno cans produce more heat than candles do.
As the oil heats and begins to flow, observe the pattern of fluid flow (circulation) by noting the location of individual flakes of thyme over time. Write down all of your observations in your lab notebook. This type of energy movement is called thermal convection, because added heat causes the fluid flow (circulation by convection) by lowering the density of the liquid.
Be sure to view the model several times during the experiment, both from above the dish and from the side of the dish.
Draw a sketch of the circulation in your lab notebook.
Measure the temperature of the oil in different parts of the model.
What is the biggest temperature difference you can find?
Record the temperature in your notebook.