What is the difference between "How long would" vs "How long will"?

What is the difference between 1-"How long would a train take to arrive here?" and 2-"How long will a train take to arrive here?" In what situation should I use the above sentences? These sentences just came into my mind so I can't provide you their context. If you know in what context I should use them, then feel free to provide it.

You have arrived at a remote station and there's no timetable. You might ask 'How long will a train take to arrive here?' (or, more simply, 'When's the next train?')

You are trying to calculate the likely arrival time of the train. You ask 'How long would a train take to arrive here if it left Anytown at 10.00?' We use would for hypothetical questions.

‘How long will it take’ Is asking a present question as if you were impatient.

‘How long would it take’ Is you thinking about something, like answering a maths questions about how long it would take for one car to travel to a certain area.