How is momentum conserved in a newton's cradle when one steel ball hits the other?
all the momentum starts in one ball, and after the collision, they share it.
all the momentum starts in one ball, and after the collision, it is all in the other ball.
both balls have momentum to start, and they share it after the collision.
momentum is not conserved in the steel balls of a newton's cradle.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

c. magnitude and direction

the rearrangement of particles in a physical change. hope this

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