The gecko is sticking upside down to a smooth ceiling. The remarkable adhesion might be due to static electricity. Gecko feet are covered with microscopic hairs. When these hairs rub against a surface, charges separate, with the hair developing a positive charge and negative charge forming below the surface. There is an attractive force between the separated charges. This is an effective means of adhering to a surface, but it comes at a cost: Two planes of charge are like two charged plates of a capacitor, which takes energy to charge. Doubling the amount of charge on each surface increases the attractive force, but also increases the energy required to separate the charge. Part A By what factor does this energy increase? (UElec){ (UElec); ΕΧΕΙ ΑΣΦ Submit Request Answer Provide Feedback ?

An old fashioned computer monitor accelerates electrons and directs them to the screen in order to create an image. How much equal charge should be placed on the Earth and the Moon so that the electrical repulsion balances the gravitational force of 1.98×10^20N ? Treat the Earth and Moon as point charges a distance 3.84×10^8m apart.

Two identical metal blocks resting on a smooth horizontal surface are connected by a lightweight spring having a spring constant k = 0.2 N/m, as shown in the figure. The length of the spring before it is stretched is L0 = 10 cm. A total charge Q is carefully applied to the block, which is assumed to be a point charge. Because the blocks are given an electric charge, the spring is stretched so that its length becomes L = 10.2 cm. Find Q!

Two identical spheres are attached to silk threads of length L=0.60 m and hung from a common point as shown in the figure. Each sphere has a mass m=7.0 g. One sphere is given a charge q1, and the other is given a different charge q2, this causes the spheres to separate so that when the spheres are in equilibrium, each thread makes an angle = 20 degrees with the vertical. A small wire is then connected to the spheres, allowing charge to be transferred from one sphere to the other until the two spheres have equal charges, the wire is then removed. Each thread now makes an angle = 30 degrees. Determine the original charge (in micro-coulomb) of q1.