a ball is dropped from the top of a 100 m tall building. what is the time it takes for the ball to hit the ground? what's the ball's final velocity the instant before it strikes the ground?

The movement of electrons between atoms is called an

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.

Is the number of complete movements of a wave per second.