BOOM. That is what you'll hear if things go 1225km/h. It's breaking the sound barrier. Welcome to the world of Mach 1. The sound almost similar to thunder is due to a phenomenon call SONIC BOOM. A mach cone is things you'll see. The best part is, to see something like this is like looking at a spaceship traveling between dimension.  Well words not gonna help you enjoy it. So lets have a look.