Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1) A proton (p) and electron (e) are released when they are 4 A (4 Angstroms) Fi

ID: 1532522 • Letter: 1

Question

1) A proton (p) and electron (e) are released when they are 4 A (4 Angstroms) Find the initial accelerations of each particle, from one of the selections below a) a(p) 8.63 x 1017 m/s2, a(e) 1.58 x 1021 m/s b) a(p) 3.4 x 1018 m/s2, a(e) 6.3 x 1021 m/s2; c) a(p) 4.315 x 1016 m/s2, a(e) 7.9 x 1020 m/s2; or d) a(p) 3.45 x 1018 m/s2, a(e) 6.32 x 1021 m/s2 2) Two small spheres are placed a distance 20 cm apart and have equal charge How many excess electrons must be placed on each sphere if the magnitude of the Coulomb repulsive force is F 3.33 x 10 21 N? a) 2 x 103; b) 350, C) 760; or d) 1.2 x 105 3) Three point charges are placed at the following positions in the x-y plane: Q, 5.0 nC at (x, y) (0,0), Q -3.0 nC at (x, y) (4 cm, 0), and Q, nC at (x, y) (2 cm,0); What is the magnitude, and sign, of charge Q1 such that the net force exerted on charge Q3, exerted by charges Q1 and Q2 is zero? a) Q,- 0.5 nC; b) Q. 0.25 nC c) Q 0.375 nC, or d) Q 0.750 nC 4) Electrostatic levitation (ESL) is a laboratory method developed at JPL for container-less processing of metal alloys under high-vacuum conditions (Pressure PN 10 Torr). The ESL apparatus layout is shown in Fig.-1. It uses a CCD camera array connected by a LabView controlled feedback loop (Fig.-2), to apply the high potentials (V required to electrostatically levitate small applied metal alloy specimens, with mass m N 30 mg between two copper electrodes inside the cylindrical-shaped high vacuum chamber (See Fig.-3, Fig.-4)

Explanation / Answer

1) Initial acceleration of proton = 8.98 * 109 * (1.6 * 10-19)2/[(4 * 10-10)2 * 1.67 * 10-27]

                                                  =   8.63 * 1017 m/s2

   Initial acceleration of electron = 8.98 * 109 * (1.6 * 10-19)2/[(4 * 10-10)2 * 9.11 * 10-31]

                                                  =   1.58 * 1021 m/s2

2)    Here, 3.33 * 10-21 = 8.98 * 109 * q2/(0.20)2

=>   q = 1.218 * 10-16 C

Thus, excess electrons =   1.218 * 10-16/(1.6 * 10-19)

                                    = 760

7) total electric flux = 14 * 0.25 * cos60

                                 = 1.75 Nm2/C2

8)   maximum total electric flux = 14 * 0.25 * cos0

                                                   = 3.5 Nm2/C2

direction = 0 degree