“probably know, the Earth is rotating on its axis. This gives us day
and night. Of course it’s impossible, but what would happen if the Earth
stopped spinning? Remember, this isn’t possible, it can’t happen, so
don’t worry.
Everything would be launched in a ballistic trajectory sideways
The first thing to think about is the momentum of everything on the
surface of the Earth. You’re held down by gravity and you’re whizzing
through space at a rotational velocity of 1,674.4 km/h (at the equator).
You can’t feel it because of momentum. Just like how you can’t feel
that you’re moving in a car going down the highway. But you feel the
effects when you stop, or get into an accident. And so, if the Earth
suddenly stopped spinning, everything on the surface of the Earth at the
equator would suddenly be be moving at more than 1,600 km/hour
sideways. The escape velocity of Earth is about 40,000 km/hour, so that
isn’t enough to fly off into space; but it would cause some horrible
damage as everything flew in a ballistic trajectory sideways. Imagine
the oceans sloshing sideways at 1,600 km/hour.
The rotational velocity of the Earth decreases as you head away from
the equator, towards the poles. So as you got further away from the
equator, your speed would decrease. If you were standing right on the
north or south pole, you’d barely even feel it.
A day would last 365 days
The next problem is that day and night wouldn’t work the same any more.
Right now the Earth is rotating on its axis, returning the Sun to the
same position every 24 hours. But if the Earth stopped spinning, it
would then take 365 days for the Sun to move through the sky and return
to the same position. Half of the Earth would be baked for half a year,
while the other hemisphere was in darkness. It would get very hot on the
sunny side, and very cold in the shadowed side.