# Two charges of # 5# # C # and # -1# # C# are positioned on a line at points # -2 # and # 1 #, respectively. What is the net force on a charge of # 1# #C# at # -1 #?

##### 1 Answer

#### Explanation:

If we imagine the situation (or, better, draw a large, clear, labeled diagram!) we know that the

(We were not told the units of distance on the line but we need to assume it was

It's also worth realising that the force on the

For the

(if we drew our number line in the usual left-to-right direction, this force is acting to the right)

For the

The net force is simply the sum of these two forces: