Question

calculate the electrical potential at a point P a distance of 1 m from either two to charge of +10 micro coulomb and -5 micro coulomb which are 10 cm apart calculate also the potential energy of a +2 micro coulomb charge placed at a point p​

Answer 1

Answer:

a)  V = 45 10³ V, b) U = 4.59 J

Explanation:

a) The electric potential for a series of point charges is

         V = k ∑ $\frac{q_i}{r_i}$

in this case point P is at a distance of 1 m from each charge, so the point is located perpendicular to the charges at its midpoint

 

         V = k ( $\frac{q_1}{r} + \frac{q_2}{r}$)

         V = 9 10⁹ (10 - 5/ 1) 10⁻⁶

         V = 45 10³ V

b) the potential energy is

           U = k (  $\frac{q_1q}{r} + \frac{q_2q}{r} + \frac{q_1q_2}{r_2}$ )

where r = 1m and r₂ is the distance between the two charges r₂ = 0.10 m

           U = 9 10⁹ (10 2 / 1 - 5 2/1 - 10 5 /0.10) 10⁻¹²

           U = 9 10⁻³  510

           U = 4.59 J