미괄식 3

[최정빈]

As we all know the art rotates on its access, the imaginary line that run through center of the earth from north pole to the south pole while it orbits to the sun.

The leghth of all days is calculated by this rotation. 

That is the amount of time the earth needs to spin completely around on its access is called a day which is 24 hours.

Now, the original cause to this rotation is uncertain but the continued rotation of the earth is believe to be a productive ? .

? of courses is the tendency of objects to resist any changes to the stable of motion.

Immoblie objects tend to stay immoblie while those in motion tend to stay in motion.

Some speculate that the earth started spinning when all solar system was borned.

And since there were no resist forces trying to slow the earth down, it keeps on spinning to this day.

Most of you might think that the length of day has been the same since the earth was formed.

But what if I would to tell you that the time the earth needs to spin completely can change.

This is what I like to talk about today.

Now, what if I would to also tell you that humans can actually change the speed of the rotaion.