[Homework Home > Coulomb's_Law] 
[1]  Four charges are oriented in a square as shown. q_{1} has charge + \mu C ,
q_{2} has charge  \mu C , q_{3} has charge + \mu C ,
q_{4} has charge  \mu C . The square has side of length a= m long.
Find the force on q_{3}, the lower left charge. 
[2]  Two charges are separated by a distance of r= m . One charge has a charge of q_{1}= \mu C ,
and the other charge has q_{2}= \mu C . What is the force of one charge on the other.

[3]  Three charges, q_{1}, q_{2}, and Q are on an axis, like this:
q_{1}= \mu C , q_{2}= \mu C , and Q= \mu C . This distance between q_{1} and q_{2} is a= m . Where should Q be placed at some point between q_{1} and q_{2}, to be in equilibrium (e.g. so it won't move?) 
[4]  Two small conducting balls, each with mass m= kg are tied
to the ends of nonconducting strings. The strings each have a length of L= m . The balls are then each given the
same amount of charge, Q= \mu C . Due to Coulomb's law, the balls repel each other, and
the system will sit with the balls separated as shown here:
By what distance will the balls be separated (find x)? 
[5]  Three charges are arranged in a triangle, as shown here
q_{1} is + \mu C , q_{2} is + \mu C ,and q_{3} is  \mu C . The triangle is equilateral, and each side has a length of a= m . What is the force on q_{1}? 
[6]  Three charges are oriented as shown here
q_{1}= \mu C , q2=+ \mu C , and q3= \mu C . The distance between q_{1} and q_{3} is r_{2}= m and the distance between q_{1} and q_{2} is r_{1}= m . q_{3} is on a line that make a \theta= degree angle with the yaxis. What is the force on q_{1}? 
[7]  Two masses (m_{1} and m_{2}) carrying equal charges, Q, are held at a distance of d= m apart.
One of the charges has a mass of m_{1}= kg . They are released. At the instant they are
released, m_{1} has an acceleration of a_{1}= m/s^{2} and m_{2} has an acceleration of a_{2}= m/s^{2} .

[8]  Three charges are arranged as shown here.
q_{1}= \mu C , q_{2}=+ \mu C , and q_{3}= \mu C . q_{1} is a distance a= m from q_{3} and q_{2} is a distance b= m from q_{3}. What is the force on q_{3}? 
[9]  Two charges, q_{1} and q_{2} have a sum of \mu C . When they are m apart, a repulsive force of N exists between them. What are q_{1} and q_{2}? 
[10]  How many electrons are in  C of charge? 
[11]  Two small metal balls are r= m apart. They repel each other with a force of F= N . What is Q on each ball? 