HW2 oscarsolution_pdf

HW2 oscarsolution_pdf - maldonado (om2892) Homework 2 Stone...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: maldonado (om2892) Homework 2 Stone (13750) 1 This print-out should have 7 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points Two small metallic spheres, each of mass . 17 g are suspended as pendulums by light strings from a common point as shown. The spheres are given the same electric charge, and it is found that the two come to equilib- rium when each string is at an angle of 6 . 8 with the vertical. 2 9 . 2 c m 6 . 8 . 17 g . 17 g If each string is 29 . 2 cm long, find the mag- nitude of the charge on each sphere. The Coulomb constant is 8 . 98755 10 9 N m 2 / C 2 and the acceleration of gravity is 9 . 81 m / s 2 . Correct answer: 10 . 2857 nC. Explanation: Let : L = 29 . 2 cm = 0 . 292 m , m = 0 . 17 g = 0 . 00017 kg , and = 6 . 8 . L a m m q q From the right triangle in the figure above, we see that sin = a L a = L sin , and the separation of the spheres is r = 2 a . Consider the forces acting on one of the spheres: F e mg T The sphere is in equilibrium horizontally summationdisplay F x = T sin F e = 0 T sin = F e , and vertically summationdisplay F y = T cos mg = 0 T cos = mg . tan = T sin T cos = F e mg F e = mg tan . From Coulombs law, the electric force be- tween the charges has magnitude | F e | = k e | q | 2 r 2 , where | q | is the magnitude of the charge on each sphere, so | q | = r radicalBigg | F e | k e = (2 a ) radicalbigg mg tan k e = (2 L sin ) radicalbigg mg tan k e = 2 (0 . 292 m) sin6 . 8 radicalBigg...
View Full Document

Page1 / 5

HW2 oscarsolution_pdf - maldonado (om2892) Homework 2 Stone...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online