Answer:
-There are no other charges nearby.
Explanation:
-There are no other charges nearby.
If there is no net charge in nearby space then the force on this charge will be ZERO
-If there are other charges nearby, they must all have the same sign as Q.
There there is nearby charge of same sign then it will have repulsion force on Q
-If there are other charges nearby, they must all have the opposite sign of Q.
if there is nearby charge of opposite sign then the force must be attraction force.
-If there are other charges nearby, the total positive charge must equal the total negative charge.
If there exist two type of charges nearby then there may exist either attraction or repulsion force on it
