Problem 71-5    Source:  Entrance Exam - UERJ - RJ - 2018.

The scheme presented in Figure 71-05 represents the metallic spheres A and B, both with mass of 10^-3 Kg and electrical charge of module equal to 10^-6 C. The spheres are attached by insulating wires to supports, and the distance between them is 1 meter . Assume that the wire holding the sphere A has been cut and that the resulting force on that sphere corresponds only to the force of electrical interaction. Calculate the acceleration, in m/s, acquired the sphere A immediately after cutting the wire.

Solution of the Problem 71-5   

First, we must calculate the force of attraction between the two spheres. To do this, using the eq. 74-01 we get:

Performing the calculation we find the magnitude of the force of attraction between the spheres, or

Now, using Newton's second law we have