Exam 1, PHYS 202 Chapters 21, 22, & 24 8 February 2006 Name________________________ 1) The charges and coordinates of two charged particles held fixed in an x-y plane are q1=+2.0 µC, x1=3.5 cm, y1=0.5 cm, and q2=-3.0 µC, x2=-2.0 cm, and y2=1.5 cm. Find (a) the magnitude and (b) the direction of the electrostatic force on particle 2 due to particle 1. 2) A non-conducting spherical shell, with an inner radius of 4.0 cm and an outer radius of 7 cm, has charge spread nonuniformly through its volume between its inner and outer surfaces. The volume charge density is the charge per unit volume (C/m3). For this shell, ρ=b/r where b=5.0 µC/m2. What is the net charge on the shell? 3) In this figure, the four particles form a square of edge length a=3.0 cm and have charges q1=+10 nC, q2=-20 nC, q3=+30 nC, and q4= -40 nC. In unit vector notation, what net electric field do the particles produce at the square’s center? 4) An alpha particle (the nucleus of a helium atom) has a mass of 6.64×10-27 kg and a charge of +2e (the charge of an electron is 1.6×10-19 C). What are the (a) magnitude and (b) direction of the electric field that will balance the gravitational force on the particle? 5) What is the magnitude of the electric field at the point (2.0 i + 3.0 j - 4.0 k) meters if the electric potential is given by V = 2.0 xy 3 z 2 , where V is in volts and x, y, and z are in meters? 6) How much work is required to set up the arrangement of this arrangement of particles if q=2.30×10-12 C, a=64 cm, and the particles are initially infinitely far away and at rest?