Why do objects fall down in same place on the rotating earth? I get that newton's first law is the reason an object falling on a high speed train will maintain the same velocity as a train and therefore appear to a train passenger to fall straight down.

But why does something on a rotating mass like earth fall down in same place? The train example makes sense to me if I ignore the rotating earth that it's on. If you fell off a spinning carousel you would fly off in a straight line like a stone from a sling right? But if you jumped straight up and down on a carousel, you would land in same spot over carousel right? If so, why?


2 Answers 2


But why does something on a rotating mass like earth fall down in same place?

But they actually don't. Drop something from high enough and, even without any effects due to wind, you will observe the object moving relative to the Earth's surface.

The reason you don't normally see these effects is because it is not noticeable over short heights, and the atmosphere can mess things up as well.

  • $\begingroup$ I was thinking more about this: so the earth is constantly rotating but it doesn't need a force to rotate. It'll rotate indefinitely.(?) But we and other masses on earth need a force on us to continue rotating along with earth? $\endgroup$
    – Jaull
    Sep 16, 2021 at 1:28
  • $\begingroup$ @Jaull If you have a new question you should make a new post asking it. $\endgroup$ Sep 16, 2021 at 4:31
  • $\begingroup$ Ok thank you I will do that $\endgroup$
    – Jaull
    Sep 16, 2021 at 14:14

Actually it is not true , it's unnoticeable in human eye,the small fraction change in displacement of the body thrown upward.As it is thrown a short distance up into the air due to inertia it falls straight or with a small fraction of displacement over the ground,but if you throw a body high enough into the air the effect becomes noticeable it will be drifted...you can surf videos over YouTube of throwing a volleyball into dam there if you can see a noticeable drift in path of the ball.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.