Basic Help

[Studyinghard]

Just have a little trouble understanding all of this. I have put my understanding in bold, if someone could correct me with my mistakes that would be great.

Longitudinal waves -

In a longitudinal wave, the particles move back and forth in the same line as the direction of the transfer of energy. So from the picture, the particles move from the transfer of energy being the handThe further away from the mean position that a particle moves before returning, the greater the amplitude of the disturbance. Not sure here about the mean positionWhen the particles around a point are all moving towards the point, there is a local compression at the point.So when all the little areas of the spring are all combined together and close up its called compressing If they are all moving away from the point, there is a local rarefaction.When they are moving away and the ones that look like big gaps they are well moving further away A particular point on the spring experiences a series of compressions and rarefactions as the energy passes along the spring (see Figure 13.2)..Not sure about this with reference to the diagram

[Akirus]

The transfer of energy is from the direction of the hand (the source) to the otherside (i.e.the right side of the picture). Think of it as energy generated by the hand, which is sent from left to right through the spring.

In wave motion, there is no net displacement; the mean position is its initial position, and no matter how much wave energy goes through, it will always return to that mean position. The amplitude is the maximum distance the particle can travel from its mean position.