Two free point charges +q and +4q are spaced apart by a distance L. A third charge is then placed in such a way that the entire system is in equilibrium. a) Determine the position, magnitude and sign of the third charge. b) Show that the balance is unstable

A dipole is centered at the origin, and is composed of particles with charges +e and -e, separated by a distance 0.3 nm along the y-axis. The +e charge is on the -y-axis and the -e charge is on the +y-axis. A proton is located at nm. What is the force on the proton due to the dipole? )N 1.35*10^-16 1.35 · 10-16 Determine where you should place an electron so that the net force (from the dipole and the electron) on the proton will be zero. пт 80 80

Three small point charges lie on a straight line in vacuum as shown. Find the distance (in m) between the left charge and the middle charge along the line such that the net force acting on the middle charge is zero. 18 μC -4.0 με 9.0 μC 0.13 m O .054 O.076 O .066 O.084

= 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

Two point charges lie along the y-axis. A charge of q1 = -8 µC is at y = 6.0 m, and a charge of q2 = -6 µC is at y = -4.0 m. Locate the point (other than infinity) at which the total electric field is zero. Need Help? Read It

1) a. You hold a ruler that has a charge on its tip 4.00 cm above a small piece of tissue paper to see if it can be picked up. The ruler has -14.0 µC of charge. The tissue has 1.00 g of mass. What is the minimum charge required to pick up the tissue paper? b. A 50.2 g ball of copper has a net charge of 2.2 pC. What fraction of the copper's electrons have been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.) c. How many coulombs of positive charge are there in 1.36 kg of plutonium, given that its atomic mass is 244 and each plutonium atom has 94 protons?

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) =