Answer:
U = 80.91 J
Explanation:
In order to calculate the electric potential energy between the three charges you use the following formula:
(1)
k: Coulomb's constant = 8.98*10^9Nm^2/C^2
q1: q2 charge
r1,2: distance between charges 1 and 2.
For the three charges you have:
(2)
You use the fact that q1=q2=q3=q and that the distance between charges are equal. Then, in the equation (2) you have:
q = 1.45μC = 1.45*10^-6C
r = 0.700mm = 0.700*10^-3m

The electric potential energy between the three charges is 80.91 J
Explanation:
The critical velocity is that velocity of liquid flow, up to which its flow is streamlined (laminar)& above which its flow becomes turbulent. It's denoted by Vc & it depends upon: Coefficient of viscosity of liquid (η) Density of liquid. Radius of the tube.
A closed space zone is one that is obstrutced in some way.
Hope this helps :)
Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. They transfer energy through matter or across space. The transfer of energy by electromagnetic waves is called electromagnetic radiation. ... The two vibrating fields together form an electromagnetic wave.