If you were on a bus......

[Glpblondie]

if you were standing at the front of a bus and jumped in the air while it was moving, would you land back on the same spot or would you land at the back of the bus as you were in mid air?

[mibn2cweus]

As long as you and the bus maintain the same velocity and direction of motion, if you jump straight up you come straight down.

[jocky]

You'd probably land on your jacksie.;-)

[naz_nomad]

you'd get chucked of for sodding about

[Loosehead]

This q has been asked many times here in varying forms. When you are on the bus you are moving, relative to the road, at the same speed as the bus so if you jump up you are going forward as well so you land where you took off from. If you trace the path from off the bus you would take an arc through the air; from on the bus you appear to go straight up and down. It's all explained by relativity.

[swansgal]

You'd probably end up in hospital.

[theprof]

You'd land on the same spot.

[Wong]

You would not necessarily land on the same spot. It depends on how long you are in the air for. Once seperated from the floor of the bus you are no longer associated with the driving force that the bus maintains. If it was an open air bus and you could jump high enough you would find yourself out on the street with the bus disappearing into the distance!

[Clanad]

All the usual suspects have given excellent responses on one of the myriad of similar questions as related by Loosehead here:

http://www.theanswerbank.co.uk/Science/Questio n227433.html

[theprof]

I think we can safely ignore the theoretical aspects of this question Wong.

Separation from the floor of the bus does not alter the fact that we are bound by the concepts laid down by Einstein - relativity still applies. This question is more appropriate to Einsteins Special Theory of Relativity rather than the General Theory.

Whichever way you look at it, the poster did say "jumped". Are you aware of someone who can jump for a sufficiently prolonged period and remain in mid-air to contradict the theory? I can't.

[Thunderchild]

wong explained it very well

[ryepie]

I fact you don't even have to bother relying on Einstein to explain that you would land on the same spot. Newton's first law of motion will do that for you quite nicely, 'every object in a state of uniform motion, will tend to stay in that state unless acted on by an external force'.

Now assuming the air in the bus is more or less motionless compared to the jumper, then the NET force applied will be pretty much zero, so there will be no resultant acceleration on the jumper because of it.

[ugly_bob]

Yep, both Einstein and Newton agreed on this. You'd land in the same place.
The only time practically that Wong's situation would happen would be throwing a ball in the air on the top deck of an open-topped bus. A (tennis say) ball would get quickly affected by air resistance and slow down (relative to the street), while the bus continued forwards at the same speed, meaning the ball would travel backwards (relative to the bus) and maybe land behind it.

[Wong]

Try it and see. It will prove my point. Newtons laws are based on perfect models and are, therefore, ideal solutions - not always realistic ones

[Catso]

Oh dear, are Mr Newton's (and Mr Einstein's) laws finally undone by Mr Wong?

(Or his he taking the p? Clue in the name)

[Loosehead]

These are known as thought experiments and are designed to illustrate the main point . Unless air resistance is part of the intended thought experiment it is taken as read to be zero for the purposes of the illustration. That doesn't of course stop the predictable pedantry .

[boobesque]

what makes you think that the bus is moving? who is to say that the earth isnt moving underneath the wheels of the bus and the bus is stationary in space

[Wong]

Thunderchild - thank you
theprof - please take time to consider the error of your ways
Catso - why did you assume I was male?
Loosehead - you're trying to blind everyone with science.
boobesque - read the post again!
Has anyone tried it yet?

[mibn2cweus]

Am I invisible? �v�

[wildwood]

To be pedantic..... you would land ever so slightly back from where you jumped up.
We can assume that for the sake of the question the bus is being propelled by the motor. When the jumpee is in the air there is no force dragging the subject forward so for that time the jumper starts to slow down with forwards motion, landing backwards from where the jump was started.

It is for the same reason that when the bus is braking, a jumper would land forward of the take-off spot.

[ugly_bob]

to be pedantic, it's not the same reason someone would land forwards if the bus was braking.

If you jump inside the bus whilst not accelerating or braking, you would land in the same place. Try it. It happens. There is no air resistance to slow you down since you're not moving through the air - the air is in the bus also and is moving at the same velocity.

If the bus is accelerating, you'll land backwards of where you took off, since you will not be accelerating for the time you are in the air, and similarly if it's braking you will land forward since you are not decelerating for the time you are in the air.

On the top deck of an open top bus, you will land backwards of the point you jumped from due to a slight deceleration due to air resistance, but it won't be a significant move.