Page 238 - Primary Five Science

Heat reflectors and heat absorbers

1. When heat falls on a shiny surface, it is reflected.

2. When it falls on a dull surface, it is absorbed.

3. When it falls on a rough surface, it is absorbed.

4. Black objects absorb most of the heat while shinny polished

surfaces reflect most heat.

Applications of this concept

 Most buildings are painted white to reflect heat and remain

cool inside.

 Refrigerators are painted white to reflect most heat and so

that they remain cool inside.

 A person who puts on a black shirt feels a lot of heat than

the one putting on a white one because black absorbs most

heat while the white one reflects it.

Temperature

Temperature is the hotness or coldness of an object or a place

Temperature is measured by and an instrument called a ther-
mometer which gives the units in degrees.

Changing temperatures

Heat energy flows from a hot object to a cooler one. This caus-

es:

 hot objects to cool down

 cool objects to warm up.