if you jump up on a moving bus, will you land on the same spot?

You will land in the same place relative to that vehicle, provided that vehicle is going at a constant speed in a constant direction.

You can try this on a train. Make sure you try it when the train is not speeding up, slowing down, or going around a corner. Jump as high as you can, and you should land in basically the same spot on the floor of the train. But if you do it while looking out the window, you will see that you are still passing objects.

This is because of inertia, described by Newton's first law.

"An object in motion will remain in motion unless acted upon by a net force."

So with no wind inside the train, and no-one pushing on you, you will land on the same spot on the floor of the train from which you jumped.

Source: http://en.wikipedia.org/wiki/Law_of_inertia

website:http://wiki.answers.com/Q/If_you_jump_up_and_down_in_a_moving_vehicle_will_you_land_in_the_same_spot_and_why