Worksheet: Electric Potential Energy of a Charged Particle

In this worksheet, we will practice using the electric fields of distribution of electric charges to determine the electrical potential energy of charges.

Q1:

An ion with twice the charge of an electron is accelerated from rest to a kinetic energy of 32.0 keV by the electric field between two parallel conducting plates. If the plates are separated by a distance of 2.00 cm, what is the electric field strength between the plates?

Proton charge is + 1 . 6 0 × 1 0 1 9 C.

  • A 2 . 5 0 × 1 0 5 V/m
  • B 1 . 6 0 × 1 0 5 V/m
  • C 5 . 0 0 × 1 0 5 V/m
  • D 8 . 0 0 × 1 0 5 V/m
  • E 1 2 . 5 × 1 0 5 V/m

Q2:

A negative hydrogen ion is a hydrogen atom containing two electrons. An electron and a negative hydrogen ion are accelerated through the same potential. Find the ratio of their speeds after acceleration, assuming the speeds are non-relativistic. Use a value of 1 . 6 7 × 1 0 kg for the mass of the hydrogen ion.

Q3:

To form a helium atom, an alpha particle that contains two protons and two neutrons is fixed at one location, and two electrons are brought in from far away, one at a time. The first electron is placed at 0 . 6 0 0 × 1 0 1 0 m from the alpha particle and held there while the second electron is brought to 0 . 6 0 0 × 1 0 1 0 m from the alpha particle on the other side from the first electron, as shown.

The charge of an electron is 1 . 6 0 × 1 0 1 9 C and the charge of a proton is + 1 . 6 0 × 1 0 1 9 C.