Answer:
D. infinitely extended in all directions
Explanation:
A semi infinite solid is infinitely extended in every direction. It has a single surface and can extend when heat is applied.
The body of a semi infinite solid is idealised, that is, when there is heat present, it expands in all directions to infinity. It can be used for a thick wall because its shape can be changed when subjected to different levels of heat near its surface.
It is also expands as heat is applied because its thickness is negligible.
This idealized body is used for earth, thick wall, steel piece of any shaped quenched rapidly etc indetermining variation of temperature near its surface & other surface being too far to have any impact on the region in short period of time since heat doesn’t have sufficient time to penetrate deep into body thus thickness can be neglected
Answer:
The distance of the object placed on the principal axis from the concave mirror.
Explanation:
In a concave mirror, the nature of the image formed formed by the object placed in front of the mirror depends on the position of the object placed in from of the mirror. It all depends on the distance between the mirror and the object placed on the principal axis.
The closer the object is to the lens, the more larger or magnified the image formed will be. For example an object placed between the focal point and the pole of a concave produces a much larger image than an object placed beyond the centre of curvature of such mirror.
The load is the weight of the rock that Jonathan lifts:

The effort instead is the force applied in input to the lever in order to lift the rock:

So, the ratio between load and effort for this exercise is

So, the ratio is 10:1.
The sound mixer will need to increase the amplitude of the sound wave produced by the singer which will increase the loudness of the sound.
<h3>Amplitude of sound wave</h3>
The amplitude of a sound wave is the maximum vertical displacement of the sound wave.
The sound mixer will need to increase the amplitude of the sound wave produced by the singer.
The increase in the amplitude of the sound wave produced by the lower tune singer will result in increased loudness of the sound.
Thus, the sound mixer will need to increase the amplitude of the sound wave produced by the singer which will increase the loudness of the sound.
Learn more about sound waves here: brainly.com/question/1199084