Question

give reasons:
1) Room heaters have shiny reflectors
2) Freezers are located at the top of the refrigerators
3) Ice cubes are stored in gunny bags
4) Kites and eagles fly without flapping their wings

Answer 1

Answer:

Room heaters have polished reflectors because bright ,polished reflectors reflect heat more efficiently and hence more heat is generated in front of the heater ,at the same time since they reflect heat the appliance or the unit is saved from getting heated or catching fire.

Freezers are always on top of a fridge due to the nature of convection. The natural law of convection is that warm air rises while cold air falls, so the freezer at the top provides cold air for the other compartments at the bottom of the freezer.

In summer ice is wrapped in gunny bags because the air filled in the fine pores of the gunny bag is an insulator of heat. The air doesn't allow heat from outside to pass through it to the ice. Thus, the ice is prevented from melting.

As the temperature changes, pockets of air move back and forth, creating wind. Birds take advantage of these wind streams, utilizing them to soar up and down without flapping their wings. One limitation of this is that a bird can only use warm air pockets to soar up and down.

Answer 2

Explanation:

1. Room heater have polished reflectors because bright, polished reflectors reflect heat more efficiently and hence more heat is generated in front of the heater

2. Freezers are always on top of the refrigerator due to the nature of convection.the natural law of convection is that warm air rises while cold air falls so the freezer at the top provides cold air for the other compartments at the bottom of the freezer

3. Ice is wrapped in gunny bags because the air is filled in the fine pores of the gunny bag is an insulator of heat . the air doesn't allow heat from outside to pass through the ice

4. air pressure change constantly as the temperature changes pocket of air move back and forth creating wind birds take advantage of these winds, stream, utilising them to soar up and down without flapping their own wings