Friction is a force in which two objects . A. Collide and move in one direction B. Are repelled from each other C. Slide against each other D. Are attracted from a distance Please select the best answer from the choices provided. A B C D.

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