Page 228 - New Medley 4 Semester 2 PDF (Merged)

a large area. The heat also

distributes over a large area. Knowledge Zone
At noon, the sun is overhead The temperature is measured
by using a thermometer.
and the sunrays fall straight A thermometer reads the
on the Earth. They stay in a temperature in degree Celsius

small area and hence the heat (°C) or degree Fahrenheit (°F). A thermometer
is more. Therefore, noon is

hotter than the morning and the evening.

Activity S E L Self-Management • Analysing/Experiential Learning

To show the effect of heat on land and water

l Take two plastic bowls. Fill one bowl with sand and the other with an
equal amount of water.
l Note the temperatures of both sand and water using a thermometer.
l Keep both the bowls in the sun for half an hour.
l Note the temperature of sand and water again. What do you observe?
Do both sand and water show the same change in their temperatures?
l Now keep both the bowls in the shade for half an hour.
l Note the temperature of the contents once again.
What is your observation now?
It is observed that land (sand) gets heated up faster and also it cools faster than water.

• Hands-on Learning
Activity

To show the effect of heat on air

l Put an empty glass bottle in the freezer for 15 minutes.
l Take the bottle out of the freezer
and stretch the neck of a balloon
over its mouth. Pull
the balloon down so that the
neck of the balloon goes all
over the rings on the neck of
the bottle.
l Ask an elder to dip the bottle
more than half in hot water filled in a container. Hold it in place. What do you observe?

The cold air inside the bottle gets heated up when the bottle is put in hot water. Also, it becomes
lighter and rises up.

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