Question

An ion accelerates from rest through a potential difference of 120. V and gains kinetic energy of 240 eV. What is the electric charge of the ion?

Answer 1

We are given the following information

Potential difference = 120 V

Kinetic energy = 240 eV

We are asked to find the electric charge of the ion.

The electric charge is given by

`q=(U)/(V)`

Where U is the kinetic energy and V is the potential energy.

Recall that 1 electron volt (eV) is equal to 1.60x10^-19 joules

`1\; eV=1.60*10^(-19)\; J`

Also, 1 V is equal to 1 J/C

So, the electric charge is

`q=(U)/(V)=(240\cdot1.60*10^(-19)\; J)/(120\; (J)/(C))=3.2*10^(-19)\; C`

Therefore, the electric charge of the ion is 3.2x10^-19 C