There are several possibilities. Here are a few that occur to me:
-- If Point-A is the summit of Pike's Peak, he may feel somewhat
short of breath.
-- If Point-A is his grandmother's house, he may feel a great sense
of pleasant anticipation.
-- If Point-A is his office on Monday morning, then he may feel
a tightening sensation in his chest.;
-- If Point-A is his home on Friday afternoon, then he feels the
effects of a slow and steady drop in his blood pressure.
I finer point might be put to it if we had any idea of where
Point-A is, and what it represents in the grand scheme
of things.
Fish swimming forward in the water, the water gets pushed backward because the fish moving forward is forcing the water to move backward, the motion forward and backward are the same, they are opposite and equal.
First of all, I is proportional V according to the Ohm's Law. R is merely a constant you need to obtain an equation. However, it is true that R changes with temperature and pressure, therefore Ohm's Law is only applicable in an invariable environment. Also this constant R is different for different materials.
So, do not get confused.
Ohm's law is not a universal law, please remember that as well. Some materials do not follow it and we call them non-ohmic conductors. I hope I helped! ^-^
Answer: 2.49×10^-3 N/m
Explanation: The force per unit length that two wires exerts on each other is defined by the formula below
F/L = (u×i1×i2) / (2πr)
Where F/L = force per meter
u = permeability of free space = 1.256×10^-6 mkg/s^2A^2
i1 = current on first wire = 57A
i2 = current on second wire = 57 A
r = distance between both wires = 26cm = 0.26m
By substituting the parameters, we have that
Force per meter = (1.256×10^-6×57×57)/ 2×3.142 ×0.26
= 4080.744×10^-6/ 1.634
= 4.080×10^-3 / 1.634
= 2.49×10^-3 N/m