Two negative and two positive point charges (magnitude QQ = 5.73 mCmC ) are placed on opposite corners of a square as shown in the figure (aa = 0.110 mm ).(Figure 1)

Two point charges each with 0.1 C of charge are  0.1m apart. Given k=9.0 X 10^9 Nm2/c2.  Find the force between two charges.

= 32.2 nC. The figure below shows a small, hollow, plastic sphere hanging vertically from a thin, lightweight thread. The sphere has a mass of 7.10 g and a uniformly distributed charge of 91 Directly below it is a second sphere with the same mass, but a charge of 92 = -58.0 nC. (Assume this second sphere is fixed in place.) The centers of the two plastic spheres are a distance d = 2.00 cm apart. 91 92 (a) What is the tension (in N) in the thread? 0.11154376 N (b) The thread will break if the tension in it exceeds 0.180 N. What is the smallest possible value of d (in cm) before the thread breaks? The analysis is the same as in part (a), including the magnitude and direction of the gravitational and electric forces. Note that Coulomb's law depends on the square of the distance d. Use the threshold value of the tension to solve for d. cm

A +30 nC charge is placed at a distance r = 5 mm from a +10 nC charge in free space. Calculate the magnitude of the force between the charges. Note: ε0=8.85x10-12 Fm-1