A theory can help create a model
A) red light
red lights are an example of an electromagnetic wave. visible lights are the only electromagnetic waves we can actually see on the spectrum. red, in particular has the biggest wavelength.
b) ocean waves
ocean waves are not an electromagnetic wave. in fact, it’s a mechanical wave. electromagnetic waves can travel through a vacuum, that is empty space, but mechanical waves cannot.
c) sound waves
sound waves are also not an electromagnetic wave. it’s a mechanical wave. you cannot hear electromagnetic waves.
d) earthquakes
an earthquake is also not an example of electromagnetic waves. it’s a mechanical wave.
hope this helps!
Answer:

Explanation:
A parallel-plate capacitors consist of two parallel plates charged with opposite charge.
Since the distance between the plates (1 cm) is very small compared to the side of the plates (19 cm), we can consider these two plates as two infinite sheets of charge.
The electric field between two infinite sheets with opposite charge is:

where
is the surface charge density, where
Q is the charge on the plate
A is the area of the plate
is the vacuum permittivity
In this problem:
- The side of one plate is
L = 19 cm = 0.19 m
So the area is

Here we want to find the maximum charge that can be stored on the plates such that the value of the electric field does not overcome:

Substituting this value into the previous formula and re-arranging it for Q, we find the charge:
