Convection and Temperature Materials Required: Two clear drinking glasses Water Bottle of red food colouring Bottle of blue food colouring A refrigerator When a body of air becomes warmer than the air around it, that body of air rises. It rises because it is lighter and less dense than the other. Warm air rises and cold air falls. When air flows this way, it’s called Convection. On a hot summer day,...

Saving Electricity Materials Required: Your Home Pencil and paper Electrical energy has been such a boon to mankind that we generally take its use for granted. We expect it to be there all the time and therefore pay no heed to it, until the time it is lost. The reasons for the loss of electrical power can range from a fault with the electric utility equipment, when strong winds can blow...

Water Purification Materials Required: An adult Smallest-size flat tuna can Salt Water Spoon Large, wide-mouth jar with lid A sunny window Use of refrigerator Most of the oceans and seas in the world are made up of salt water. When the water evaporates, what is left behind is salt. But is evaporated water still salty? Let us evaporate some salt water and check if it is still salty, or whether the...

Using Solar Cells Materials Required: Three hobby solar cells Small DC hobby motor Insulated jumper leads with alligator clips on each end Several wooden blocks The solar cell, also known as the Photovoltaic cell, has the ability to convert light into electricity. Due to the difficulty in manufacturing, they are used as the last resort to obtain electricity. It is only a ‘series’ of solar cells that can generate adequate electricity....

Trapping Solar Heat Materials Required: Five glasses of the same size Water Construction papers of different colors Adhesive tape Thermometer Energy from sunlight makes heat. Light from the sun is trapped when it hits an object, making it warm, but it bounces back after hitting something light. Take five glasses of water filled to the brim and wrap a black construction paper around one. Similarly, wrap a different colored paper around...

Trapped Heat Materials Required: Two small, plastic butter or margarine tubs Plastic food-wrap Two thermometers Soil Water Is plastic bag efficient in keeping warmth? Fill two small, plastic butter or margarine tubs with soil. Add water to the soil and mix it. Push a thermometer into the middle of each tub containing mud. Set both the tubs around a warm, sunny window for one hour. An hour later, pick up the...

Wind Energy Materials Required: Pencil Thumbtacks Thread Solar cells and windmills may soon be the primary source of transmitting electricity into our houses. To find out, how a windmill can produce energy, you could construct one of your own and see the results for yourself. However, you need to know where to place your windmill first. You need to find the place, where the wind is the strongest, for the windmill...

Soap That Lasts Materials Required: An adult Paper and pencil Four small chunks of different brands of soap Four pieces of paper Four glasses of lukewarm water Soap comes very handy in bathing, washing and cleaning. There are many brands that endorse soap in the market today. Some are good while others are not. Today, we are going to find out which soap lasts the longest with the help of this...