Answer:
An Empty Tank Is Slowly Filled With Air. Water Is Then Added To The Tank, Decreasing The Volume For The Air In The Tank. The Temperature Remains Constant
Explanation:
To solve this problem we will apply the concepts related to the Electrostatic Force given by Coulomb's law. This force can be mathematically described as
Here
k = Coulomb's Constant
Charge of each object
d = Distance
Our values are given as,
d = 1 m
a) The electric force on charge 
is
Force is positive i.e. repulsive
b) As the force exerted on will be equal to that act on 
,
Force is positive i.e. repulsive
c) If 
, a negative sign will be introduced into the expression above i.e.
Force is negative i.e. attractive
<span>This is best understood with Newtons Third Law of Motion: for every action there is an equal and opposite reaction. That should allow you to see the answer.</span>
Are there supposed to be multiple choices for this question?
Scientists could investigate this idea by making cathode ray tubes out of different materials to see if the ray was the same.
