Two point charges of mass m each are suspended in the gravitational field of the Earth by two non-conducting massless strings, each of length 1, attached to the same fixed point. The spheres are given equal charges Q of the same sign. As a result each string makes angle a to the vertical (see figure below). Write down an expression for the tension of a string T in terms of Coulomb force Fc between the charges and the angle a. Use the following notation (without the quotes): "/" for division, "*" for multiplication, "+" an "_" as usual. For powers used "^2", while for square root use "sqrt". To indicate that square root applies to the whole expression use brackets - for example, for √AB use sqrt(A*B). For Greek letters such as л, α etc. use pi, alpha. For example to get 14√AB use 1/pi*A^2/B*sqrt(AB). Please use the exact variables given in the conditions of the problem: e.g if L is given, then do not use 1. For subscripts such as Fc simply write "FC" (without the quotes). Please use "Display response" button to check the you entered correct expression, before submitting your answer. B d e M M E

Two hard rubber spheres, each of mass m = 14.9 g, are rubbed with fur on a dry day and are then suspended with two insulating strings of length L = 5.25 cm whose support points are a distance d = 3.06 cm from each other as shown in the figure below. During the rubbing process, one sphere receives exactly twice the charge of the other. They are observed to hang at equilibrium, each at an angle of 0 = 10.4° with the vertical. Find the amount of charge on each sphere. (Enter your answers from smallest to largest.) с C Need Help? Submit Answer m Read It L 18 m

Two charged spheres each have charges of 700 nC and masses of 0.04 kg. They are suspended from two very light strings at an angle of 0 = 8°. Find the distance between the spheres.

A charge of 4.20 mC is placed at each corner of a square 0.100 m on a side.   Determine the direction of the force on each charge. Assume that the positive x-axis is directed to the right.