Lab Kinetic Theory and Heat Transfer

I. Kinetic Theory and the Pulse Glass

1. Place both hands on the pulse glass bulb that has more fluid. What happens to the fluid

inside the pulse glass?

2. What does your hands do to the air inside the pulse glass bulb?

3. Heating up air molecules causes them on average to move ______(faster or slower).

4. Faster air molecules cause molecules to collide with the fluid (more or less) ______frequently and with (greater or less)______energy.

II. Conduction Lab

Part 1.

Procedure:

1.  Assemble the materials as shown in the diagram below.

2.  Fill one cup with cold water and the other with hot water. Quickly cover both cups.

3.  When the thermometer in the hot cup reaches its highest temperature, record the temperature as Time 0 (in the Results section). Immediately record the temperature of the cold cup.

4.  Continue recording temperatures every minute for a total of ten minutes.

Results:

Discussion Questions:

1.  In which direction did the heat energy flow, toward the hot cup or toward the cold cup?

2.  What type of heat transfer is occurring?

3.  Predict what would happen to the temperatures of the two cups if the experiment were to continue for a longer period of time.

Part 2

Procedure

1.  Blow up a balloon and fill another balloon with water

2.  Light a candle that sits at the bottom of a glass tank.

3.  Bring the balloon filled with air next to the candle’s flame.

4.  Now bring the balloon filled with water next to the candle’s flame.

Observations:

1.  What happen to the balloon filled with air when it touched the flame?

2.  What happen to the balloon filled with water when it touched the flame?

3.  Why did the balloon filled with water not pop?

4.  What happen to the heat from the candle when it touched the balloon filled with air?

5.  What happen to the heat from the candle when it touched the balloon filled with water?

6.  What type of heat transfer occurred?

III. Convection Lab

Fill in the blanks

How does a lava lamp work?

Liquid motion lamps (which most people know as "l______lamps") have been around for decades. The theory behind a liquid motion lamp goes something like this:

In the lamp you have two liquids which are:

  • Very close in density
  • Insoluble in one another

Oil and water are ______in one another (that's where the expression "oil and water don't mix" comes from), but oil and water have very different densities (a volume of water weighs a lot more than the same volume of oil). They won't work, so you search to find two liquids that are very close in density and are insoluble.

Now you apply heat to the bottom of the mixture. In a liquid motion lamp, the heat usually comes from a ______bulb. The heavier liquid absorbs the heat, and as it heats up, it expands. As it ______it becomes less dense. Because the liquids have very similar densities, the formerly heavier liquid is suddenly lighter than the other liquid, so it rises. As it rises, it cools, making it denser and therefore heavier, so it sinks.

This all happens in slow motion because heat absorption and dissipation are fairly slow processes, and the density changes we are discussing here are very slight.

1. What type of heat transfer occurs in a lava lamp?

IV. Radiation Lab:

A.  Radiometer

Observation of Radiometer / Distance from light bulb (cm)
2
20
60
100

1.  What happens to the radiometer when it gets close to a light source?

2.  What happens to the radiometer when it further away from a light source?

3.  What are the colors of the radiometer vanes? (Hint read the box of the radiometer)

4.  What side of the radiometer vanes absorbs a lot of energy? (Hint read the box of the radiometer)

5.  What type of heat transfer is occurring with the radiometer?

B.  Build a solar motor

Procedure

1.  Follow the instructions on the back of the solar instructional kit to put together the solar motor.

2.  Attach the fan blades to the motor.

3.  Place the solar cell near a light.

Observations:

Location of solar cell / Observation of rate of fan spin
Near light source
Away from light source
Change the angle of the solar cell with respect to the light source

1. What type of heat transfer is occurring with the solar cell?

C.  Radiation cans

Procedure:

1.  Put thermometers into the black and silver cans and position the stoppers so they are not touching the bottom of the cans

2.  Record the temperatures of both cans

3.  place the cans next to a heat lamp

4.  Record the temperatures of both cans after 5 minutes.

Observations:

Original temperature C° / Temperature in C° after 5 minutes under heat lamp
Black can
Silver Can

1.  Which can absorb the most energy?

2.  Which can reflect the most energy?

3.  What type of heat transfer is occurring with the radiation cans?

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