Answer:

Explanation:
Given that,
A radio wave transmits 38.5 W/m² of power per unit area.
A flat surface of area A is perpendicular to the direction of propagation of the wave.
We need to find the radiation pressure on it. It is given by the formula as follows :

Where
c is speed of light
Putting all the values, we get :

So, the radiation pressure is
.
V = I * R
Where V is the voltage, I is the current and R is the resistance. Using Ohm's law, you require resistance to find the current through the wire. Technically, if the wire has a resistance of 0, you will get infinite current. But this isn't possible. Maybe the negligible resistance refers to the battery's internal resistance - not the wire's resistance.
Answer:
The crest to trough distance = 8 m
Explanation:
Given that,
The amplitude of a particular wave is 4.0 m.
We need to find the crest to trough distance.
We know that,
Amplitude = The distance from the base line to the crest or the the distance from the baseline to the trough.
It means,
Distance from crest to trough = 2(Amplitude)
= 2(4)
= 8 m
Hence, the crest to trough distance is equal to 8 m.
The correct answer to this question is D