Which statements describe acceleration? Check all that apply. Negative acceleration occurs when an object slows down in the positive direction.
Negative acceleration occurs when an object slows down in the negative direction.
Negative acceleration occurs
when an object speeds up in the negative direction.
Positive acceleration occurs when an object speeds up in the positive direction.
Positive acceleration occurs when an object speeds up in the negative direction.
Positive acceleration occurs when an object slows down in the negative direction.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

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