Answer:
0.027 J
Explanation:
The formula of the potential energy in electrostatic (U) is

The values given in the question are
Charge : q = 
Electric Field strength : E = 
Distance : d is 0.030 m
Insert in the formula , will give us

Further solving it

Which is the required answer.
Thanks
The electric field strength is inversely related to the square of the distance.so the strength of the electric field is given by

Here,
is constant depend upon medium and its value is
and q is charge and r is the distance.
Given
and we know the charge of proton,
.
Therefore,

Answer:
P = 2 pi R / v period of space station
F / m = v^2 / R centripetal force per unit of mass
So F / m = 4 pi^2 R^2 / (P^2 * R) = 4 pi^2 R / P^2
Also, F / m = 9.8 m/s^2 earth's gravitational attraction
So 9.8 = 4 pi^2 R / P^2 or R = 9.8 P^2 / 4 * pi^2) = 195 m
Or D = 2 R = 390 m the diameter required
Answer:

Explanation:
The constant speed means that ball is not experimenting acceleration. This elements is modelled by using the following equation of equilibrium:


Now, the exerted force is:

The volume of a sphere is:



Lastly, the force is calculated:

