SP212‐Spring‐2016 CH‐21 Assignment First do the following Wiley‐Plus assignment: Assignment #21 After completing the Wiley‐Plus, in your homework notebook, complete the following problems: CH21 Question # 3. CH21 Problems  No additional problems are assigned this assignment. Good problems to look over if you have time, but are not assigned are: #6, 28, and 47. To check your work, the answers to the odd problems are in the back of the book. The answers to the even problems are: #6) a) m2  4.9 x10 7 kg b) q  7.1x1011 C #28) n  2.25 x1020 If you cannot get these answers you should be seeking help from your instructor. Homework Then complete the attached worksheets: (Note: the above problems were designed to ensure you have the skills to solve the worksheet problems. It is imperative to your learning of the problem solving technique to do the above problems BEFORE attempting the worksheet problems. You are graded on both! Homework notebooks are graded too.) CH‐21‐1: For each of the equations below, 1) State what each term is in your own words … 2) What the units of each term are… 3) What is the general use of that equation in your own words? 
A. FE 
k q1 q2
rˆ ,includehowyouknowthedirectionof .
r2
B. q  ne C. i 
dq
dt
CH‐21‐2: Given the following diagram and following charge values, what is the net electrostatic force (magnitude and angle) on charge q3? Charges q1 = ‐q2 = 320 nC and q3 = ‐q4 = 95 nC, and distance a = 6.6 cm. Show all work including vector diagrams! CH‐21‐3: In Fig. below, particle 3 with charge q3 is to be moved along the axis between particle 1 (charge q1 = ‐ 2e) and particle 2 (charge q2 = +16e). (a) At what coordinate x (in terms of d) is the magnitude of F3, net of the net force on particle 3 least? (b) What is the value of that minimum force if it is assumed that d= 8 cm? Show all work: CH‐21‐4: A particle of Q is fixed at the origin of an XY coordinate system. At t=0 a particle (m=.772 g, q=668 μC) is located on the x‐axis at x=30 cm, moving with a speed of 55.0 m/s in the positive y direction. For what value of Q will the moving particle execute circular motion neglecting the gravitational force on the particle? Show all work: CH‐21‐5: In the figure below, two tiny conducting balls of identical mass m and identical charge q hang from non‐conducting threads of length L. Assume that  is so small that can be approximated by
. gives the equilibrium separation of the balls. (a) Show that Show all work:` (b) If Show all work: ,
,
. , then what is | |?