1. The problem statement, all variables and given/known data q1= 6.7 μC q2= -4.5 μC q3= 2.2 μC q4= 2.2 μC d= 7.7 cm What is the x-component of the net force on q1? 2. Relevant equations 3. The attempt at a solution This is part of an online problem set, and is currently the only question I have not answered correctly. I find it strange because I have approached it the same way as similar problems in the problem set (ex. What is the x-component of the net force on q2?) so I have a hard time understanding where I am going wrong. Perhaps someone can help, so here goes my thought process. So the obvious one to start with is the force exerted on q1 by q2 since the x-component is the entire force. Plugging in values of q1= 6.7 μC, q2= -4.5 μC and d= 0.077m to the above equation gives a force of -45.258 N. Moving on to the force on q1 by q4. By plugging in q1= 6.7 μC and q2= 2.2 μC with d= 0.077m we get 22.126 N for the entire force. To get the x-component of this force, I then multiplied by cos(60) because it is an equilateral triangle and got an answer of 11.063 N. Since q3=q4 and they are at the same distance from q1 with the same angle, I assumed the x-components of their forces would be the same, so i multiplied by 2 and got back to 22.126 N once again. When adding them all up, I get 22.126 - 45.258 = -23.132 N. SmartPhysics says this is wrong. I disagree! What do you guys think? Have I made a very obvious mistake somewhere along the way?