# A charge of #-2 C# is at the origin. How much energy would be applied to or released from a # 4 C# charge if it is moved from # (7 ,5 ) # to #(3 ,-2 ) #?

##### 1 Answer

Let

The distance formula for Cartesian coordinates is

Where

Distance between origin and point P i.e

Distance between origin and point Q i.e

Distance between point P and point Q i.e

I'll work out the electric potential at points

Then I will use this to work out the potential difference between the two points.

This is the work done by moving a unit charge between the two points.

The work done in moving a

The electric potential due to a charge

Where

So the potential at point

The potential at

So the potential difference is given by:

So the work done in moving a

This is the work done on the charge.

There are no units of distance given. If this was in meters then the answer would be in Joules.