hi,

this is my first post..i am a 9th grader so don't pounce on me if you find my questions idiotic...i want to learn..anyways,one problem,

earth's rotational speed is 493.8m/s..now if i jump from a point on earth's surface so that i stay in air for 1 s..when i land , i should end up 493.8m away from where i started as by the time i reach land ,earth should have moved 493.8m ahead(or behind) me..but i land on the same point from where i started !!!!!!!!!!!!

how can this happen as earth will surely move ahead in 1s....

pls explain this...

Before you jump, you (and the surrounding atmosphere) are moving at that same speed. So you not moving relative to the earth, and that's what matters.

 

Similarly, consider someone in a train or car going by at 10 m/s. They throw a ball up in the air. To them, it goes straight up and down — they don't notice that they are moving. Someone on the ground sees the ball already moving at 10 m/s, and sees the ball move in a parabola. The situation with jumping on the earth is almost the same (there are some situations where the circular path will make a difference, but probably not for a 1-sec jump). An outside observer would see you jumping in a parabola, going at the rotational speed.

welcome!

This problem if im not mistaken has puzzled many early physicists. Pretty much, that because of the fact that you and the earth were going at the rotational speed in the beginning (you are on the earth, and the earth is moving 493.8m/s, you are on the earth, you thus go the same speed) when you jump up you actually have traveled 493.8 meters (given you jump for one second) you just dont experience the horizontal movement because by the time you moved 493.8 meters the earth has also moved that far. your not moving because of your relative position, which is that of someone on the earth.

 

Now if an astronaut was looking at you he would of seen you travel that far. Bc of his relative placement to the earth.

 

Get it?

thanks both of u....now i get it..