A hoop is thrown onto the ground without bouncing. Initially the velocity of the center of the hoop is to the right at 2 m/s, and it has a backspin of 5 rad/s. What will be the speed and direction of the center of the hoop when it stops slipping relative to the ground

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me

answerscientific theory;

where is the