Hello.
BEVs and hydrogen fuel cell vehicles are a more promising transportation technology for the future because they reduce greenhouse gas emissions as well as CO2 making it more 'green.' The second question is your opinion, in mine no, they should not be required but they should at least be considering.
Have a nice day
Answer:
Friction of the road on the motorcycle in the opposite direction
Explanation:
Khanacademy
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.
