Answer:
"The distance between crests is 3 cm."
Explanation:
If he writes down "The distance between crests is 3 cm."
That means he is describing the wavelength of a wave and not longitudinal wave. He ought to write something about " direction "
Longitudinal waves are waves in which the displacement of the medium is in the same direction as, or parallel to, the direction of propagation of the wave. While
Wavelength is the distance between the two successfully Crest or trough
equal and opposite reaction.
Explanation:
Though the diagram that is mentioned in the questions is not given. I have given general information related to the Earth's magnetic axis with respect to geographic/rotational axis.
Axis is an imaginary line around which a body rotates. The rotational axis of the Earth enters into and exits from the Earth at two points namely: North and South pole.
We know that the Earth behaves like a huge bar magnet so just like the bar magnet it must also have magnetic axis and poles. Earth has north magnetic pole and south magnetic pole. It has a strong magnetic field as well known as magnetosphere.
The interesting point about magnetic axis is that it is not same as rotational axis. In fact it makes an angle with the rotational axis. This is known as magnetic inclination. This inclination varies at different points on Earth.
Another interesting point is that the geographic and magnetic poles are opposite. That means near the geographic north pole we have the magnetic south pole and vice versa.
The answer is true, is called Thermal pollotion:).