Two charges, Qa and Qb, are located 20 cm apart. When a third charge is placed at the x mark, 10 cm from Qb, the electric force on Qc is zero. Find the value of Qb

Three particles are held in place along the X-axis. One particle has a charge of 25 C and is located at the origin. Another particle (with a charge of 30 uC) is located at x=10 cm. The last charge is located at ×=-15 cm. What must be the amount of charge on the third particle, if the charge located at the origin is in equilibrium (i.e. all the forces cancel)?

Two particles, one with charge -7.13 µC and one with charge 3.55 µC, are 6.59 cm apart. What is the magnitude of the force that one particle exerts on the other? force: TOOLS 93=== Two ne x10 entical positive charge qs, are placed the same 6.59 cm apart, and the force between them is measured to be the same as that between the original particles. What is q? N HC

A 148 mg plastic bead has a radius of 344 μm and is charged by the addition of 1.38×1010 excess electrons. You may assume that the excess electrons are spread uniformly throughout the bead. What electric field strength will cause the bead to hang suspended in the air?

A 8-g charged plastic sphere charged to 75 µC is on top of a plastic spring with spring constant k = 400 N/m, which has a relaxed length of 10 cm. You then place another charged object 1 cm above (not touching) the sphere. Now, the spring is 9.5 cm long. Find the charge on the new second object.

Four point charges, q1 = 8.2 uC, q2 = -7.8 uC, q3 = 1.7 uC and q4 = -5.9 uC, are arranged in a square with side lengths L = 7.5 cm. What is the magnitude of the electric field at the centre of the square?

A charge +q is located at the origin. A charge - 2q is at 3.15 m on the x axis. (a) For what finite value of x is the electric field zero? 7 Xm To the right of both charges, which charge is always closest? Does it have the smaller or larger charge? At what locations are there two field contributions that can cancel to produce zero net field? (b) For what finite value(s) of x is the electric potential zero? x m Because the charge of -2q is closer than the charge of +q for this value of x, the 2q dominates and the total field cannot be zero. m smaller value larger value

Two charged spheres on a frictionless horizontal surface are attached to opposite ends of a string & are in static equilibrium. The 39 kg red sphere has more charge than the 22 kg green sphere. The total charge magnitude on the spheres is 120 ?C & they have the same polarity. As a result the tension is 202.5 N & the centers of the spheres are 0.39 m apart. Find the charge magnitude on each sphere. Qred (bigger charge) = Qgreen (smaller charge) =