# How would gravity change on a planet rotating around itself very fast?

Let's take a planet identical to Earth, but with rotation speed multiplied by ten thousand. What would happen with the gravity if it was spinning madly around itself? Would the centrifugal force make objects seem lighter than on normal Earth? Would the people on that planet be able to jump higher?

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Possible duplicates: physics.stackexchange.com/q/44931/2451 , physics.stackexchange.com/q/10670/2451 , and links therein. –  Qmechanic May 7 '13 at 0:57
Also related: physics.stackexchange.com/questions/12487/… –  Brandon Enright May 7 '13 at 1:02
I'm not as interested in the effects on the planet as on the objects on it. –  user1306322 May 7 '13 at 1:20

Okay, This question has assumed a lot. I think you're aware that Earth's (spin) rotational velocity (around 30 m/s) is the left over velocity after the Earth had formed from the dust clouds and matter. If on the contrary, you were to assume its spin to be multiplied by 10k x suddenly: first - the outer layers would wither off. Finally, you'd be left with Earth made of barely some mantle (maybe the outer core which would've cooled out). Depending on the remaining mass of the Earth $(M_{left}<\frac{1}2M_{before}$ for sure $)$, the $g$ would be less than 9.8 and so, yes - people can jump higher...
So, to be clear,you're saying that the effects of the hyperspin would cause a decrease in $g$, but the hyperspin itself wouldn't? –  WChargin May 7 '13 at 3:18
Hi @WChargin: Yes. If the Earth doesn't lose its mass, how come there would be any noticeable effect on the $g$ value? But, there wouldn't be existence of any other objects other than the matter that Earth was made of..! Because, that wizardo matter can only withstand the hyperspin. Others would be thrown away (assuming current size of Earth) ;-) –  Waffle's Crazy Peanut May 7 '13 at 11:47