What is the correct definition of a rarefaction? Orin a medium through which sound is passing, a zero-pressure region of a sound
wave
in a medium through which sound is passing, a low-pressure region of a sound
wave
in a medium through which sound is passing, a low-altitude region of a sound
wave
in a medium through which sound is passing, a high-pressure region of a sound
wave

Agroup of students were investigating the force of gravity. they began by dropping a foam ball from a height of 3 meters into a bucket of sand. the ball hit the sand in 0.306 seconds. they dropped additional balls of approximately the same diameter, but of different masses. here is the data they collected. based on this experiment and the collected data, what would their conclusion be?

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

The mantle is made up of which structural zones?