4) a) write the unit for energy in the mks in basic (also called core or axiomatic) units.
b) show the unit break down to get from ib/slugs to ft/s .

i need to show me the graph so i can give u an answer

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