Un excursionista se dirige a una montaña que se encuentra a 6 kilómetros al norte de su casa. Convierta los 6 km a pies y haga una figura de la situación.​

the higher the current the higher the mag field around it the higher the influence on the compass

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

3. dark matter

empty space could also be a simple vacuum