Hot air _ and cold air _ due to _
A. falls; rises; gravity
B. rises; falls; gravity
C. rises,; falls; bouyancy
D. falls; rises; boyancy
C. rises, falls; bouyancy
4. Convection does NOT occur in *
• gases
• liquids
solids
• fluids
solids
5. Radiation allows heat to travel through empty space (a vacuum) without a medium.
True or false?
True.
The correct answer is C. Hot air rises and cold air falls due to buoyancy.
The correct answer is: C. rises; falls; buoyancy
Hot air rises and cold air falls due to buoyancy. Buoyancy is the upward force exerted by a fluid (in this case, the air) on an object immersed in it. The air is made up of particles that are constantly in motion due to the heating and cooling processes happening in the atmosphere.
When air is heated, the particles gain energy and move faster, which causes the air to expand and become less dense. As a result, the hot air becomes lighter than the surrounding cooler air and starts to rise. This is because the buoyant force acting on the hot air is greater than its weight, causing it to be pushed upwards.
On the other hand, when air is cooled, the particles lose energy and move slower, causing the air to contract and become denser. The cooler air becomes heavier than the surrounding warmer air and starts to sink down. In this case, the buoyant force acting on the cool air is less than its weight, leading it to fall.
This process of hot air rising and cold air sinking due to differences in density is known as convection. It plays a crucial role in various atmospheric phenomena such as weather patterns, wind circulation, and the formation of clouds and storms.