HOW TO PROVE AIR EXPANDS WHEN HEATED????

Let's prove air expands when heated!!!!!

Materials:

1 plastic cup

Water

Balloon

Glass test tube

Tape

Instructions

Fix the balloon to the test tube use tape to ensure it is attached firmily to the test tube (do not blow the balloon)

Boil water and pour the boiled water  in the plastic cup and put the test tube with the balloon inside the water (make sure that only the bottom of the test tube should touch the water)

Observe: After 1 or 2 minutes the balloon is heated . This proves that when air is heated it expands

TO PROVE HOT AIR IS LIGHTER THAN COLD AIR!!

Let's prove hot air is lighter than cold air!

Materials:

2 cloth bags
1 candle
1 hanger

Instructions

Tie the cloth bags at the ends of the hanger. ( One at each end)

Hold the hanger from the hook, at an equal balace.

Now ask a friend to light the candle and heat one of the bags make sure that the flame of the candle does not touches the bags.

Observe: The bag that was heated rises up .

This proves hot air is lighter than cold air.

USING AIR TO CRUSH AN ALUMINIUM CAN!!!

Let's take the help of air to crush a aluminum can!!!


Materials:


Aluminum can

Saucepan

Kitchen toungs

Water

Cold water

Instructions

Fill the saucepan with cold water.

Now fill the can with 2-3 teaspoon of room temperature water.

Heat the can until the water inside starts to boil. ( You would see vapour cloud when the water starts to boil)

Let the water boil for 30 seconds.

After 30 seconds quickly grab the can with the KITCHEN TOUNGES and put it in the saucepan upside down



What is happening???



The water vapor created from heating the can pushed air out of the can. When the can is inverted and placed into the cold water, the water vapor in the can condenses quickly. Like the egg in the bottle experiment, the pressure in the can decreases quickly. The outside pressure is much higher than inside which causes the can to collapse!