To develop this problem we will apply the concepts related to the potential energy per unit volume for which we will obtain an energy density relationship that can be related to the electric field. From this formula it will be possible to find the electric field required in the problem. Our values are given as
The potential energy, 
The volume, 
The potential energy per unit volume is defined as the energy density.
The energy density related with electric field is given by
Here, the permitivity of the free space is
Therefore, rerranging to find the electric field strength we have,
Therefore the electric field is 2.21V/m
Each magnet has a north pole and a south pole. We know that, from having played with bar magnets in our childhood, that a magnet's north pole will repel another magnet's north pole and attract its south pole.
From this diagram it is easy to see that the two lower bar magnets not only repel each other, but they are quite attracted to each other since their north and south poles are close together.
Therefore the region between the lower two magnets has the least force of repulsion.
Answer:
A) F_g = 4.05 10⁻⁴⁷ N, B) F_e = 9.2 10⁻⁸N, C) 
= 2.3 10³⁹
Explanation:
A) It is asked to find the force of attraction due to the masses of the particles
Let's use the law of universal attraction
F = 
let's calculate
F = 
F_g = 4.05 10⁻⁴⁷ N
B) in this part it is asked to calculate the electric force
Let's use Coulomb's law
F = 
let's calculate
F = 
F_e = 9.2 10⁻⁸N
C) It is asked to find the relationship between these forces
= 2.3 10³⁹
therefore the electric force is much greater than the gravitational force
<span>D is the correct answer. A Bourdon gage is a popular and commonly used kind of gauge for measuring pressure and vacuum. One use for a Bourdon gage is to indicate steam pressure.</span>
