what if the earth stopped spinning?

Everyone and everything one the side facing away from the sun would become insanely cold-like Mercury, where the 'dark side' is around -200 degrees even though it's 'day side' is really hot. It doesn't matter as much for the terrestrial planets how far they are from the sun, but orbits play a rather big part in it. So...yeah, half the life on earth would die (besides maybe flatworms in the depths of the ocean-they seem to be able to live through anything), and the other half would eventually die as well because Earth needs motion to generate the magnetic field, which would in turn eventually strip the planet of its atmospheres and kill us with the sun's UV rays.

one side of the earth would be really cold the other side would be really hot curenlty the moon is slowing the earth down becasue its rotation around us but very little so its nothing to worry about it would take a very very long time before that happens and when it dose we will have the tecnolgy to move to another planet or make it keep rotating

Stuff would suddenly move at up to 25,000 mph, the speed depending on how far away from one of the poles it was.

The only place that might be safe is on the South pole.

To answer this we would have to know the cause. If it was some kind of giant set of brake shoes the effect would be significantly different than some kind of Star Trek inertial dampener.

.

The same thing that happens when you are driving in a car and suddenly slam on the brakes. Except much much worse.