Answer:

Explanation:
The strength of the electric field produced by a charge Q is given by

where
Q is the charge
r is the distance from the charge
k is the Coulomb's constant
In this problem, the electric field that can be detected by the fish is

and the fish can detect the electric field at a distance of

Substituting these numbers into the equation and solving for Q, we find the amount of charge needed:

Answer:
<h2>7.21 J</h2>
Explanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 2.060 × 3.5
We have the final answer as
<h3>7.21 J</h3>
Hope this helps you
I think the answer is C. I am not be right
The answer is -23.
I hope this will be of use to you