when you say the air forced against it? Do you mean the surface of the back of the bus would push the air at the back into the air at the front which compresses it?
Yes! When the bus accelerates, it sort of immediately leaves the air at a standing start and the back of the bus is driving into the air....but the void that is left at the front of the bus is immediately filled creating the push or higher pressure onto the people on that bus which you feel as a force on you as long as the bus accelerates.
you mean when the bus slows down the air at the front of the bus will collide with the bus and the air towards the back will collide with the air in front of it because it is now moving faster than the bus?
When the bus slows down.let's say an emergency stop.
As soon as the brake is applied, the opposite happens, except more violently. Let's assume the bus was doing 50 mph, so we know that the air inside of it is moving at 50 mph which is fine as long as the bus is at that constant speed. If the driver slams his foot on the brake, you get a 50mph force of pressure...not steady wind....pressure, there is a massive difference, because during that violent emergency stop...not only has the air just went forward...it has done so whilst creating a low pressure which is filled constantly for the duration of that stop. It's a massive pressure build up and you feel it act violently on your back forcing you forward....
As soon as that bus stops dead...the air pressure quickly equalizes, which means it expels the excess pressure from the bus that you feel as a jolt backwards again.
Can you see what I'm saying?
I was talking hypothetically. So the more air the bus needs to move the more force it would need in order to shift the air. You could have the same size bus but pressurized air inside if it makes it easier to think of.
I'm not quite sure what you are getting at with this question. It appears to be a kind of question designed to trip me up for some reason. If I'm wrong the fair enough.