Three equal charge 1.8*10^-8 each are located at the corner of an equilateral triangle ABC side 10cm. calculate the electric potential due to these charge at the mid point of AB​

If all these three charges are positive with a magnitude of each, the electric potential at the midpoint of segment would be approximately .

Explanation:

Convert the unit of the length of each side of this triangle to meters: .

Distance between the midpoint of and each of the three charges:

Let denote Coulomb's constant (.)

Electric potential due to the charge at : .

Electric potential due to the charge at : .

Electric potential due to the charge at : .

While forces are vectors, electric potentials are scalars. When more than one electric fields are superposed over one another, the resultant electric potential at some point would be the scalar sum of the electric potential at that position due to each of these fields.

Hence, the electric field at the midpoint of due to all these three charges  would be:

.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.