Un protón está moviéndose hacia el este, y experimenta una fuerza de 8,8 x 10-19 N hacia arriba debido al campo magnético de la Tierra. En ese punto el campo tiene una magnitud de 5,5 x 10-5 T hacia el norte. Encuentre la velocidad de la partícula.

scientific laws are the result of testing theories and proving them to be facts.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

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