Question

I WILL GIVE 100 POINTS!!

You have learned that heat moves from warm areas to cooler ones. In solids, heat is transferred by the physical touching of molecules. This type of heat transfer is called conduction. Some materials, like metal, conduct heat better than other materials. In fluids (liquids and gases), heat is transferred by convection currents caused by differences in density.

MATERIALS
hot water
cold water
metal fork
plastic fork
stick of cold butter
large glass
watch or clock with a second hand
yellow and blue food coloring
playing card
four empty, identical plastic bottles (sports drink bottles work well)
access to a sink

QUESTIONS
Part 1
What type of heat transfer is demonstrated in Part 1?
How long did it take for the butter to melt off of the plastic fork? The metal fork?
How do explain the difference in time between the two forks?
Part 2
What type of heat transfer is demonstrated in Part 2?
What happened when the warm water bottle was placed over the cold water bottle? Why?
What happened when the cold water bottle was placed over the warm water bottle? Why?

Answer 1

Pt. 1

In gases and liquids, heat is usually transferred by convection, in which the motion of the gas or liquid itself carries heat from one place to another. ... If you boil water in a kettle, the heat is transferred through convection from the fire to the pot.

Pt. 2

This motion of fluids is called convection. In the set of bottles where the hot water was above the cold water, the cold water was already on the bottom, so there was no convection.

Pt. 3

When the bottle was put into the cold water, the air in the bottle contracted, taking up a smaller space in the bottle. The sides of the bottle pushed in when the air inside controlled