A helium nucleus (charge = 2e, mass = 6.63 10-27 kg) traveling at 6.20 105 m/s enters an electric field, traveling from point circled A, at a potential of 1.50 103 V, to point circled B, at 4.00 103 V. What is its speed at point circled B?

Explanation:

It is given that,

Charge on helium nucleus is 2e and its mass is

Speed of nucleus at A is

Potential at point A,

Potential at point B,

We need to find the speed at point B on the circle. It is based on the concept of conservation of energy such that :

increase in kinetic energy = increase in potential×charge

So, the speed at point B is .