# A charge of #-1 C# is at the origin. How much energy would be applied to or released from a # -3 C# charge if it is moved from # ( -1, -3 ) # to #(-2 ,7 ) #?

##### 1 Answer

#### Answer:

#### Explanation:

The -3C charge moves from

I will work out the electric potential due to the charge at the origin at points

Then I will subtract these to get the potential difference between the 2 points in volts

If 1C of charge is moved through a potential difference of 1 Volt then 1 Joule of work is done.

So I will then multiply the potential difference by -3C to get the total work done.

**Potential at P:**

This is given by:

To find

**Potential at Q:**

Again, we can use Pythagoras to find

To get the potential difference

To get the work done

The negative sign means work must be done on the charge to move it from

No units for distance are given. If it was in metres then