Step 1 : Get your supply list together
Step 2 : Pick what model you want to do
Step 3 : Ask for a partner 
Step 4 : Complete  the model and take your time.
Step 5 : Read the directions carefully 
        
             
        
        
        
Okay, haven't done physics in years, let's see if I remember this.
So Coulomb's Law states that 

 so if we double the charge on 

 and double the distance to 

 we plug these into the equation to find
<span>

</span>
So we see the new force is exactly 1/2 of the old force so your answer should be 

 if I can remember my physics correctly.
 
        
        
        
Speed has the dimensions of distance divided by time. The SI unit of speed is themetre<span> per second, but the most common unit of speed in everyday usage is the kilometre per </span>hour<span> or, in the US and the UK, miles per </span>hour<span>. For air and marine travel the knot is commonly used.</span>