A charge of +3 micro-coulombs is attached to a string and another charge of -3 micro-coulombs is placed below the charge as shown. When the charge on...

A charge of +3 micro-coulombs is attached to a string and another charge of -3 micro-coulombs is placed below the charge as shown. When the charge on the string is in equilibrium, the angle between the string and the vertical is 15 degrees, the angle between the charges and the vertical is 27 degrees, and the distance between the charges is 3.3 cm. What is the mass of the charge of the string in kg?