Give reasons for the following. (a) Cool air sinks and warm air rises up. (b) Moving air provides a lift. (c). the front portion of a wind vane has a smaller surface area than its rear portion.
Answers
Answer:
Explanation:
a) Hot air rises because when you heat air ,it expands.
When the air expands, it becomes less dense than the air around it.When something is hot, its molecules are farther apart than when it is cold.So it takes up more room.
that makes hot air lighter than cold air, because the cold air has more molecules in the same amount of room
b) The flowing air provides a lift as it decreases the pressure and provides motion in opposite direction.
c) The front part of the wind vane has smaller surface area than its rear part because when the wind blows it presses more on rear part so that it aligns in the direction. So the front part is smaller than the rear part
a) Hot air rises because when you heat air ,it expands. When the air expands, it becomes less dense than the air around it.When something is hot, its molecules are farther apart than when it is cold.So it takes up more room.
That makes hot air lighter than cold air, because the cold air has more molecules in the same amount of room
b) The flowing air provides a lift as it decreases the pressure and provides motion in opposite direction.
c) The front part of the wind vane has smaller surface area than its rear part because when the wind blows it presses more on rear part so that it aligns in the direction. So the front part is smaller than the rear part