Use your calculator to determine (√7) to the third power to three significant figures in two ways.
(a) find √7 to four significant figures; then cube this number and round to three significant figures.
(b) find √7 to three significant figures; then cube this number and round to three significant figures.
which answer is more accurate?
explain.

answer and explanation;

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

gravitational energy

electrical energy

kinetic energy

ligh energy