Answer:
Electric field due to two charges is given as

Explanation:
As we know that two charges are opposite in nature
So the electric field at the mid point of two charges will add together
so the net field is given as

now we have


now we have


Answer: 117.6N
Explanation:
By the second Newton's law, we know that:
F = m*a
F = force
m = mass
a = acceleration
We know that in the surface of the Earth, the gravitational acceleration is g = 9.8m/s^2.
Then we just can input that acceleration in the above equation, and also replace m by 12kg, and find that the force due the gravity is:
F = 12kg*9.8m/s^2 = 117.6N
The answer is actually 36 J.
Hope this helped :)
Brainliest?
Solution :
a). Using Gauss's law :
,
.........(1)
Let
in equation (1)
Therefore,
.............(2)



....................(3)
Therefore, 

.............(4)
Now differentiating the equation (4) w.r.t. 'b', we get
Thus the radius for the inner cylinder conductor is 
b). For the energy storage, substitute the radius in (4), we get

This is the amount of energy stored in the conductor.
Answer:
C
Explanation:
b is 55 miles per hour south or 55mph[South]
the important part to understand is that velocity is a vector meaning it also has to have a direction, in this case south. That is why a (2m/s) is not a velocity, however 2m/s is a speed.