Science 8 Instructions
Lab: Heat Transfer
Purpose: To investigate the three methods of heat transfer.
Materials: radiometer, meter stick, heat lamp w/ stand, foam cups, lids, digital thermometers, conduction bar, timer, 250 ml glass beaker, candle, matches, ring stand, wire screen, tongs, food color, textbook, hot plate, jugs of room temperature water.
Procedure:
A. Radiation
1. Position the radiometer (looks like a weird light bulb) 30 cm from the lamp and turn on the lamp.
a. Write your observations.
2. Position the radiometer 60 cm from the lamp.
a. Write your observations. What happened?
b. Look up and write the definition for radiation.
c. What caused the vanes inside the radiometer to turn?
Give your best guess.
3. For 5 more minutes of your time at this station, experiment with the radiometer. Try to measure how fast the vanes turn at different distances from the light. I would recommend starting with 80 cm. Focus on one vane and count spins / 15 seconds. Make a table and graph of your data. Tilt to stop.
4. Turn off the lamp and put the radiometer near the lamp.
Leave neat for the next group.
B. Conduction
1. Quickly, make a table like shown at the bottom of the page.
2. Use the tongs to carefully fill one cup up to the line with very hot water.
Fill the other cup to the same level with room temperature water.
3. Place the lids and thermometers on the cups with the ends of the U shaped bar going into the water in each cup.
4. Turn on the thermometers.
a. Record the temperature of the water in each cup.
This is time 0. Start the timer.
b. Record the temperature again each minute for 5 minutes.
Look up and write the definition for conduction.
Run a finger along the bar from one side to the other.
c. Write about what you observed.
d. Check the temperatures again. What does the timer read now?
e. What do you think would happen if you performed this experiment for 1 hour?
f. How is conduction demonstrated in this experiment?
Empty the water out of the two containers, reset the timer and prepare the setup for the next group. Turn off the thermometers.
C. Convection
1. Put 200 ml of room temperature water in the 250 ml glass beaker.
2. Position the ring so that it is about 2 cm above the candle.
3. Place the wire screen on the ring on the ring stand.
4. Set the beaker of water on the screen so that the candle is just to the side of the bottom of the beaker. Not in the middle.
5. Put one drop of red food color in the beaker.
a. How does the color spread? Write your observations.
5. Light the candle.
6. Observe the beaker for the next couple of minutes.
7. Put one more drop of green food color into the beaker from the opposite side of where the candle is.
a. Write your observations.
b. Is it different from before?
c. Look up and write out the definition for convection.
d. How does this experiment demonstrate convection?
8. Blow out the candle.
9. Empty the beaker and set it on the table.
10.Observe the lava lamp for a minute.
a. How does the lava lamp demonstrate convection?
Leave the table neat for the next group.
Lab: Heat Transfer ver. 2.2 Page 1 of 3