Answer: The correct explanation is 2.
Explanation: The warm air is less dense (it expands) and thus it is lighter than the cold air so it will rise up to the floor. Therefore, when you place the heater on the floor it will warm the cold air which would then rise and be replaced by more cold air which would again get warm and rise and so on until the room is heated. This means that the correct explanation is 2.
On the other hand, if you put the heater at the ceiling, it will warm the cold air near the ceiling which would stay up there (it is lighter than the cold air under it). This means that the only way for the heat to spread from this ceiling level warm air to the lower levels is via conduction which is slow.
more deceleration.
in vertical motion downwards => terminal velocity ... raindrops etc
Answer:
D
Explanation:
The atomic number of hydrogen is 1, because hydrogen is considered the number #1 element in the periodic table. Hope this helps!
Answer:
elasticity
1.price elasticity of demand
2.income elasticity of demand
3.cross elasticity of demand
4.elasticity of supply
Explanation:
1. price elasticity of demand is the degree to which the effective desire for something changes as its price changes. In general, people desire things less as those things become more expensive.
2. income elasticity of demand is the responsiveness of the quantity demanded for a good to a change in consumer income. It is measured as the ratio of the percentage change in quantity demanded to the percentage change in income.
3. cross elasticity of demand or cross-price elasticity of demand measures the responsiveness of the quantity demanded for a good to a change in the price of another good, ceteris paribus.
4.price elasticity of supply is a measure used in economics to show the responsiveness, or elasticity, of the quantity supplied of a good or service to a change in its price.
