- 1 matchbox
- 1 candle
- 1 yellow colored balloon
- 1 blue colored balloon
- Half a cup of water
1. For this experiment, the independent variable is whether the balloon is filled with water or not. The dependent variable is what happens to the balloon when it is placed above the lit candle. This is determined by observing the balloon. The constants (control variables) are how much the balloon is inflated and the amount of water in the balloon.
2. Inflate the yellow colored balloon and tie it up.
3. Pour half a cup of water into the blue colored balloon before inflating it to the same size as the yellow color balloon and tie it up.
4. Light up the candle. Be careful when using match sticks to avoid causing fires, or burning yourself.
5. Hold the yellow colored balloon on top of the lit candle. Observe and record what happens.
6. Hold the blue colored balloon on top of the lit candle. Observe and record what happens. How the Strength of a Magnet Varies with Temperature
Materials and Equipment
To do this experiment you will need the following materials and equipment: * safety glasses,
* 5–10 permanent iron magnets of equal size and strength, * thermometer (minimum range 0–100°C),
* tongs for holding magnets (preferably plastic, for minimizing heat transfer), * dry ice (frozen CO2),
* water ice,
* insulated containers to hold ice and dry ice,
* thick insulated gloves for handling dry ice,
* small pot,
* stove or hot plate for heating water,
* 2 large plastic bowls,
* at least one box of standard #1 paper clips,
* if you have a really strong magnet, you may need more than one box, * test the magnet at room temperature first, and make sure that there are plenty of paper clips left over (see Experimental Procedure, below), * alternatives to paper clips: small steel BBs or nails. Experimental Procedure
Note: this experiment is designed for testing the temperature dependence of permanent magnets not electromagnets. 1. You will test each magnet at four different temperatures: a. −75°C, the temperature of dry ice (don't try to use the thermometer for this one!), b. 0°C, the temperature of a water ice bath,
c. 20°C, room temperature,
d. 100°C, the temperature of boiling water.
2. Wear safety glasses when heating, cooling, and transfering the magnets. Always use tongs for handling magnets at extreme temperatures. 3. Before measuring each magnet's strength at a given temperature, allow the magnet to equilibrate to the test temperature for at least 15 minutes. 4. To test magnetic strength, follow these steps:
e. Use the tongs to place a magnet into a bowl filled with paper clips (or steel BB's). f. See how many clips (or BB's) the magnet can lift out. g. Set the magnet and paper clips (or BB's) down in an empty plastic bowl. h. Wait until they are safe to touch before counting the number of paper clips (or BB's). i. Record the number in your lab notebook for each magnet and temperature tested. j. It's a good idea to practice handling the magnets with tongs at room temperature first until you get the hang of it. Make sure your results are reproducible at room temperature before trying the experiment at extreme temperatures. 5. For each temperature, calculate the average number of objects each magnet picked up. 6. Make a graph of magnetic strength, as measured by number of objects lifted (y-axis), vs. temperature (x-axis). 7. Does magnetic strength increase, decrease, or stay the same over the temperature ran
The Egg inside a Bottle Experiment.
For the Egg in a Bottle experiment, you will need the following items: * hard boiled egg
* bottle with an opening narrower than the size of the egg * matchbox