Unit 10: Weather Experiments
Make a Cloud in a Jar:
- Glass Jar
- Hair Spray
- Ice Cubes
- Hot Water
- Food Coloring
- Optional: Plate to place the jar on
- Die the water with food coloring (easier to see the cloud if you do this step)
- Carefully pour hot water into the jar, so it’s a little less than half-way full.
- Have the lid to the jar ready to go. Spray a little bit of hairspray and quickly put on the lid
- Place a couple of ice cubes on top of the jar
- Watch the cloud form!
Clouds form when water vapor rises and condenses on to tiny particles (in this case the hair spray). The warm water in the jar allows it to heat and some of the water is evaporated in the jar causing water vapor. Once that warm air rises to the top of the jar it gets cooler bu the ice cubes. When water vapor cools, it then condenses on the hairspray particles and forms a cloud.
Learn About Density
- Two Eggs
- Two Glasses
- Pour enough water into one glass until it is almost full.
- Stir is about 6 tablespoons of salt
- In the other glass, fill with water until it is nearly full.
- Carefully, drop the egg into the glass that has no salt in it. Watch what happens.
- Now, drop another egg into the glass that has salt in it. Watch what happens.
This experiment is to learn about density. Notice, the glass that does not have salt in it, the gg just falls to the bottom. This is because the egg is denser than the water. When you add salt, it makes the water denser and in turn, the egg floats at the top.
Tornado in a Jar
- Glass Jar
- Clear Liquid Soap
- Fill the jar with water, 3/4 full
- Put a teaspoon of liquid soap and a teaspoon of vinegar in the jar
- Tighten the lid and shake until the ingredients mix up
- Swirl the jar in a circular motion and you will see a small tornado form
When you swirl the bottle, that forms a vortex and simulates a tornado in the jar.
Make Your Own Thermometer
- Clear, Plastic Bottle
- Rubbing Alcohol
- Clear Plastic Drinking Straw
- Modeling Clay
- Food Coloring
- Fill the bottle 1/4 of the way with equal parts water and rubbing alcohol
- Add a few drops of food coloring
- Place the star in the bottle without touching the bottom
- Seal the bottle with modeling clay so the stay stays put
- Holds your hands on the bottle and watch the mixture in the bottle move up into the straw
The mixture that you made in the bottle will expand when it’s warm, just the air in the atmosphere when it’s warmer outside. The mixture no longer fits in the bottom of the bottle and must go somewhere. As the picture expands it moves up into the straw.
Make a Thunderstorm
- Clear Container (Size of a Shoebox)
- Red Food Coloring
- Ice Cubes Made with Blue Food Coloring
- Fill the container 2/3 full with lukewarm water
- Let the water sit for a minute
- Place a blue ice cube at one end of the container
- Add three drops of red food coloring to the water at the opposite end
This simulates what a cold front does. The cold, blue ice cube will sink, while the warmer red water rises, which in weather we call convection. The blue ice cube indicated a cold air mass, while the red water, indicates warm, unstable air. This shows how a body of warm air is forced to rise by an approaching cold front where thunderstorms form.
You can also track thunderstorms. After you see a strike of lightning (safely from inside), use a stopwatch to count the number of seconds until you hear thunder. For every 5 seconds that equals one mile. So if you count 10 seconds, then the thunderstorm is 2 miles away.
Build an Anemometer to Measure Wind Speed
- 5 paper cups (3oz size works the best)
- 2 Plastic Straws
- Hole Punch
- Thumb Tack
- On one paper cup, punch 4 equally spaced holes, along with one punch on the bottom of the cup.
- On the 4 remaining cups, punch one hole about 1/2″ below the rim
- Take one of those cups and place the straw in the hole and bend a little part of the straw on the inside and stable it in place. Repeat this with the other straw and another cup.
- Slide one of those through two holes that you made in the first cup. On the other end of the straw, take one of the other cups from Step 2 and staple the straw in place. Make sure the cups are facing in opposite directions. Repeat this will the remaining cups
- Each open side of the cup should face the closed side of the cup in front of it.
- Take the Thumbtack and align the straws so they insect and push through. Take you pencil and slide through the bottom hole on the cup made in Step 1 and push the tack into the eraser
- Now you can take this outside and watch the cups spin or just use your breathe or a hairdryer.
An anemometer is used to measure wind speed. On a weather station, it measures how many times that anemometer spins in a minute and using an equation to calculate wind speed in miles per hour.
Make Your Own Rain Gauge
- Plastic Bottle (Water Bottle or Two Liter Bottle)
- Masking Tape
- Permanent Marker
- Cut the top of the bottle off
- Fill the bottom with some pebbles, rocks, tor stones to prevent it from blowing over.
- Turn the top of the bottle that you cut off upside down and place it into the bottle. Tape in place to make sure the edges line up.
- Take a piece of tape and make a straight vertical line from the top to the bottom of the bottle. 0″ should be at the bottom of the bottle.
- Take your ruler and mark every quarter inch.
- Carefully pour water into the bottle until you reach the 0″ mark.
- When rain is the forecast, pick a good spot to place your rain gauge. An open place where it won’t get too windy and where the gauge won’t be disturbed by other things, like water off of a rooftop or under a playground. After 24 hours, grab your rain gauge and see how much rain fell
Make Frost in a Jar
- Crushed Ice
- Blue Food Coloring
- Color water blue and set aside
- Fill the jar up about 3/4 of the way full of crushed ice
- Add a 1/2 inch layer of salt
- Pour the blue water over the salt
- You can add the lid to the jar if you want and give it a quick shake to speed up the process
- A thick layer of ice crystals should then form on the surface of the jar
A jar of ice water is very close to the freezing temperature to make condensation but not normally frost. When you add salt to the mixture, salt lowers the melting point of ice. The jar then falls below the freezing point and turns condensation to frost.