Question

A charge, q1, of +15 micro-coulombs is located at x= 0, y=9.4 cm, a charge of q2, of -44 micro-coulombs is located at x=0, y= -3.8 cm, an unknown charge of q3, is located at x= -3.5 cm, y=0 cm, and a charge, q4, -9 micro-coulombs is located at x= +14.9 cm, y= 0 cm. The direction of the total electric force on q4 is 145.5 degrees from the +x axis, counter-clockwise. What is the unknown charge q3, in micro-coulombs? If negative, include a negative sign in your answer.

A charge of +1.6 micro-coulombs lies on a horizontal surface. It has a mass of 2 kg and the coefficient of static friction between it and the surface is 1.75. Another charge of -3.3 micro- coulombs lies on the horizontal surface 11 cm to the right of the charge. A third charge which is negative is located 10 cm above the positive charge on the surface. What is the smallest magnitude this charge needs to be in order for the positive charge to overcome static friction such that the negative charge on the surface begins to move it? Answer in micro-coulombs. 93 qi q2

Answer 1