Asmall rocket is launched vertically, attaining a maximum speed at burnout of 1.0 102 m/s and thereafter coasting straight up to a maximum altitude of 1528 m. assuming the rocket accelerated uniformly while the engine was on, how long did it fire?
and how high was it at engine cutoff?

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