• Question: Suppose, I am standing on earth’s equator and jumped vertically up to 500ft. when I arrive back on earth’s surface, will I still be on the same position where I left from? NOTE: the spin of the earth is 1038mph at the equator.

    Asked by waveicle to Adam, Sheila, Suzie on 24 Mar 2011 in Categories: .
    • Photo: Suzie Sheehy

      Suzie Sheehy answered on 24 Mar 2011:

      Hi there, great question again!
      Normally in a similar situation, say in an aeroplane travelling at 1000mph, you wouldn’t move relative to the position you jumped from – because you are moving at the same speed as the plane and all the air is also moving at the same speed. There is no acceleration and you haven’t applied a force to stop you travelling forward at 1000mph, so you just jump straight up and down.
      When I first thought about this, I though it might not be exactly the same on the Earth is because the Earth is round, and if you could do a big enough jump then the surface of the Earth is moving on a curve, (which involves a bit of acceleration) whereas you will be travelling in a straight line forward, so that might change things a little tiny bit! But I decided I was wrong, as you have the force of gravity pulling you toward the centre of the Earth, so maybe this would mean you would end up in exactly the same spot?

      A thought provoking question, thanks!
      Don’t forget to keep voting 🙂

    • Photo: Sheila Kanani

      Sheila Kanani answered on 24 Mar 2011:

      You could work this out using trigonometry. I imagine you would have moved a few feet.

Comments

  • Photo: waveicle

    waveicle commented on :

    What if aeroplane departures from Brazil to Uganda and also back from Uganda to Brazil at constant speed, but because earth is spinning at one direction i.e. clockwise. Doesn’t it mean that the aeroplane from Brazil to Uganda has to cover less distance and longer distance for the aeroplane from Uganda to Brazil?

    • Photo: Suzie

      Suzie commented on :

      Well if you go from UK to the USA there is the jet stream to contend with, a high atmospheric prevailing wind. Between Brazil and Uganda I’m not sure if there is one… but if there is no prevailing wind, then since the plane travels through the air not through space it is the same in either direction. It doesn’t matter that the earth is rotating, we rotate with it.

      Think about jumping or a hot air balloon, the surface of the Earth is moving really fast but if you jump you don’t see it suddenly move underneath your feet or the balloon suddenly go really fast in one direction.

  • Photo: waveicle

    waveicle commented on :

    @suzie, THANKS! very descriptive answer.