let us consider that the two charges are of opposite nature .hence they will constitute a dipole .the separation distance is given as d and magnitude of each charges is q.
the mathematical formula for potential is 
for positive charges the potential is positive and is negative for negative charges.
the formula for electric field is given as-
for positive charges,the line filed is away from it and for negative charges the filed is towards it.
we know that on equitorial line the potential is zero.hence all the points situated on the line passing through centre of the dipole and perpendicular to the dipole length is zero.
here the net electric field due to the dipole can not be zero between the two charges,but we can find the points situated on the axial line but outside of charges where the electric field is zero.
now let the two charges of same nature.let these are positively charged.
here we can not find a point between two charges and on the line joining two charges where the potential is zero.
but at the mid point of the line joining two charges the filed is zero.
Answer:
The time taken will be 0.553 seconds.
Explanation:
We should start off by finding the force exerted by the rope on the 3kg weight in this case.
Weight of 5kg mass = 5 * 9.81 = 49.05 N
Weight of 3kg mass = 3 * 9.81 = 29.43 N
The force acting upward on the 3kg mass will equal the weight of the 5kg mass. Thus the resultant force acting on the 3kg mass is:
Total force = 49.05 - 29.43 = 19.62 N (upwards)
We can now find the acceleration:
F = m * a
19.62 = 3 * a
a = 6.54 m/s^2
We now use the following equation of motion to get the time taken to travel 1 meter:


t = 0.553 seconds