Question

A point charge of 4.0 µC is placed at a distance of 0.10 m from a hard rubber rod with an electric field of 1.0 × 103 . What is the electric potential energy of the point charge?

× 10–4 J

What is the electric potential energy of the point charge at 1.3 m?


× 10–3 J

Answer 1

The electric potential energy of the point charge is 4.

the electric potential energy of the point charge at 1.3 m is 5.2.

Answer 2

Part 1)

`U = 4 * 10^(-4) J`

Part 2)

`U = 5.2 * 10^(-3) J`

Step-by-step explanation:

Electric field due to rubber rod is given by

`E = 1.0 * 10^3 N/c`

now we also know that

`V = E. r`

`V = (1.0 * 10^3)(0.10)`

`V = 1.0 * 10^2`

now potential energy is given as

`U = qV`

`U = (4 \mu C)(1.0 * 10^2)`

`U = 4 * 10^(-4) J`

Similarly the electric potential at distance r = 1.3 m

so we have

`V = (1.0 * 10^3)(1.3)`

`V = 1.3 * 10^3 Volts`

now potential energy is given as

`U = (4\mu C)(1.3 * 10^3)`

`U = 5.2 * 10^(-3) J`