Answer:
B
Explanation:
The correct answer is B) have unlike charges. Since they are attracted to each other they have to be unlike
I'd say diffraction since sound waves can bend around objects like corners. Let's say you're in the hallway and you can hear sound coming from a door. The sound waves diffract around the door and spread out into the hallway, making it possible for you to hear.
Also, you can hear it before you see it because light waves are shorter than sound waves and hardly diffract around doors.
<span>C.
Sample C would be best, because the percentage of the energy
in an
incident wave that remains in a reflected wave from this material
is the
smallest.
The coefficient of absorption is the percentage of incident sound
that's absorbed. So the highest coefficient of absorption results in
the smallest </span><span>percentage of the energy in an
incident wave that remains.
That's what you want. </span>
Gravity ALWAYS does that, and electrostatic force does it when two objects have opposite charges.
Beat frequency, fb = |f2-f1|
That is, beat frequency is the absolute difference between two frequencies. Is is as a results of destructive and constructive inferences.
Therefore, in this case:
fb = 203 - 199 = 4 Hz