1) 
The capacitance of a parallel-plate capacitor is given by:

where
is the vacuum permittivity
A is the area of each plate
d is the distance between the plates
Here, the radius of each plate is

so the area is

While the separation between the plates is

So the capacitance is

And now we can find the energy stored,which is given by:

2) 0.71 J/m^3
The magnitude of the electric field is given by

and the energy density of the electric field is given by

and using
, we find

The only 'difference' is that they are different categories.
It's like asking "What's the difference between Susie and girl ?"
Or "What's the difference between Cadillac and car ?"
Displacement <em>IS</em> a vector quantity.
We have that for the Question "Write an expression for the <em>magnitude </em>of charge moved, Q, in terms of N and the fundamental charge e" it can be said its equation is

From the question we are told
Write an expression for the <em>magnitude </em>of charge moved, Q, in terms of N and the fundamental charge e
<h3>An E
xpression for the <em>magnitude </em>of charge moved</h3>
Generally the equation for the <em>magnitude </em>of charge moved, Q is mathematically given as

Therefore
An expression for the <em>magnitude </em>of charge moved, Q, in terms of N and the fundamental charge e" it can be

For more information on this visit
brainly.com/question/16517842
The elastic potential energy of the spring is 0.31 J
Explanation:
The elastic potential energy of a spring is given by

where
k is the spring constant
x is the compression/stretching of the spring
For the spring in this problem, we have:
k = 500 N/m (spring constant)
x = 0.035 m (compression)
Substituting, we find the elastic potential energy:

Learn more about potential energy:
brainly.com/question/1198647
brainly.com/question/10770261
#LearnwithBrainly