electric es, Using Eq. (1.1), F =[910' N.m/C +7.5x10 CX+7.5x10 C) (0.0872 m) -6.65810 N710 N. pub iniog ning D Practice Exercises 1.3 1. Determine the ratio of the electric force to the gravitational force between an electron and a proton when separated by a distance r. Spheres A and B have the same initial positive charge qo. The magnitude of the repulsive electric force between the two spheres is 14.4 N when separated by a distance of 0.03 m. (a) Find the initial charge qo. (b) The spheres are then allowed to touch each other and then separated. Find the electric force between them if the radius of sphere A is three times that of sphere B. Szolgy lown-one Chapter 1 Shocking! 17 A proton and an electron are initially at rest at a distance of 910-1 m. What will be their initial acceleration due to the electric force that they exert on each other? 4. A small sphere of charge +610-6 C is suspended from a string of negligible mass. A charge of -9.0x10C is placed directly to the right of the sphere and 0.22 m away from it. The string is deflected 5 from the vertical. Find the tension in the string. Superposition Principle So far, only the force between two point charges has been discussed. What if there are more than two charges? For instance, if there are three charges 4, 92, and q, what will be the net force on q, due to q and q? d 2 on 1 92 -T3 on 1 Fiel 2 on 1 The net for 3. Given: q: 250x1 92.50 r-100m z=-3.0 x1 Solutio S by 9 Po -1 -0.07615 N = tan -0.03635 N = 64.5. m001) (m 00 Thus, the resultant force is 0.0844 N directed down at 64.5 with the negative x-axis as shown. 1. 2. Practice Exercises 1.4 Using the same charge configuration in Sample Problems 1.4 item number 1, find the resultant electric force on q Using the same charge configuration in Sample Problems 1.4 item number 2, find the resultant electric force on the charge at vertex B. 3. Suppose that the charges in Sample Problems 1.4 item number 3 are situated as shown. Find the resultant electric force on the charge at A. +9 1.00 m 9A 6 A B daug low 3 bl 1.00 Cena Hiw D 8 awob bar Science Patrol bookliv bo A aga su no Researchers at Indiana University led by Dr. Chandan Sen have developed an electroceutical fabric that can kill coronavirus within a minute upon contact. The fabric is made of polyester printed with microcell batteries when dampened, either by water or by bodily fluids such as saliva and vapor from alternating circular metal dots of elemental silver and zinc metals. This array of metal dots activates as cough or sneeze. When activated, the microcells generate a weak electric field that ch E