Page 50 - Science Class 6 Times Publication

rough base, the foods are cooked faster than in the pots having shining
and smooth base. Our hair is hotter than other body parts when we
walk or sit in the sun shine.

What are the reasons behind these observations?

Black and rough objects absorb heat easily. They are good absorbers
of heat. Whereas white, shining and smooth substances cannot absorb
heat as much as the black objects do.

The substances which absorb heat easily are called heat absorbers.
The black objects are good absorbers of heat.

Activity 4.8

To show that black objects are good heat absorbers

Materials required: Two beakers, black polish, brush, water,
thermometers, etc.

Procedure

1. Take two beakers.
2. Polish outside of one of the beakers
with black colour.
3. Fill half of both the beakers with
water.
4. Keep the both beakers in the sun
shine for about half an hour.

5. Measure the temperature of water
of both beakers. What will you
 nd?

Observation: The water of black beaker gains higher temperature
than the water of another beaker.

Conclusion: Black substance is good absorber of heat. Therefore,
black substance can absorb more heat than other substances.

Uses of absorption of heat
Black and rough substances are good absorbers of heat. Therefore,
they are used in various types of heating devices.

Times' Crucial Science and Environment 46 Book 6