Answer:
The correct answer is d
Explanation:
In this exercise they ask us which statement is correct, for this we plan the solution of the problem, this is a Doppler effect problem, it is the frequency change due to the relative speed between the emitter and the receiver of sound.
The expression for the Doppler effect of a moving source is
f ’= (v / (v- + v_s) f
From this expression we see that if the speed the sound source is different from zero feels a change in the frequency.
The correct answer is d
Explanation:
A molecule can be made up from same or different elements. Whereas a compound will have different atoms.
Therefore, the difference between a molecule and a compound is that a compound is made up of atoms from different elements.
For example, 
is a molecule and NaCl is a compound.
And a chemical change creates a new substance.
The fragment of an asteroid or any interplanetary material is known as a a : D. Meteroid
Human came in contact with this material mostly because it penetrate the atmosphere and fall within the earth surface
hope this helps
Answer:
Option B
Explanation:
Looking at the 3 galvanometer readings given above, for galvanometer A, the reading is -2 mA.
For galvanometer B, the reading is 4 mA.
While for galvanometer C, the reading is -5 MA
Thus, option B is correct.
