The work of the electrostatic field when moving a point charge of 3.6 mC from point A to point B is 0.9 J.

The work of the electrostatic field when moving a point charge of 3.6 mC from point A to point B is 0.9 J. Find the electrical potential at point A, if at point B it is equal to 180v.

Data: q (mixed point charge) = 3.6 mC (3.6 * 10-3 C); A (perfect work) = 0.9 J; φB (potential at point B) = 180 V.

To express the potential of the field at point A, we will use the formula: A = q * (φБ – φA), whence φA = A / q – φБ.

Let’s calculate: φA = φБ – A / q = 180 – 0.9 / (3.6 * 10-3) = -70 V / m.

Answer: The potential at point A is -70 V / m.