I assume you mean rotates at 1,200 mph, but where are you getting this figure from?.
Earth spins on its axis once in every 24-hour day. At Earth’s equator, the speed of Earth’s spin is about 1,000 miles per hour (1,600 km per hour). The day-night has carried you around in a grand circle under the stars every day of your life, and yet you don’t feel Earth spinning. Why not? It’s because you and everything else – including Earth’s oceans and atmosphere – are spinning along with the Earth at the same constant speed.
It’s only if Earth stopped spinning, suddenly, that we’d feel it.
We don’t feel Earth rotating on its axis because Earth spins steadily – and moves at a constant rate in orbit around the sun – carrying you as a passenger right along with it.