# hw 5 - wilson (kw22588) HW5 Mackie (20224) 1 This print-out...

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

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: wilson (kw22588) HW5 Mackie (20224) 1 This print-out should have 10 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points A charge of 10 . 853 nC is uniformly distributed along the x-axis from- 3 m to 3 m. What is the electric potential (relative to zero at infinity) of the point at 5 m on the x-axis? Correct answer: 22 . 537 V. Explanation: Let : x 1 =- 3 m , x 2 = 3 m , q = 10 . 853 nC = 1 . 0853 10- 8 C , and k e = 8 . 98755 10 9 N m 2 / C 2 . The equation for the electric potential with the reference at is V = k e integraldisplay d q r . Since the charge is uniformly distributed along the x axis, the linear charge density is simply = q L , where L is the length of the line of charge. Hence d q = d x = q L d x . Further, the distance from the point 5 m on the x axis to a charge element is r = 5- x . Thus V = k e q L integraldisplay x 2 x 1 d x 5- x = k e q L ln parenleftbigg 5- x 1 5- x 2 parenrightbigg = 8 . 98755 10 9 N m 2 / C 2 1 . 0853 10- 8 C 3 m- (- 3 m) ln parenleftbigg 5 m- (- 3 m) 5 m- 3 m parenrightbigg = 22 . 537 V . 002 10.0 points The uniformly charged sphere gives a reason- able model of the proton charge distribution in an atomic nucleus. A nucleus of lead-208 has a radius of 5 . 582 10- 15 m and contains 82 protons, each with a charge of 1 . 6 10- 19 C. Calculate the electric potential at the sur- face of this nucleus. Correct answer: 2 . 11244 10 7 V. Explanation: Let : r = 5 . 582 10- 15 m , e = 1 . 6 10- 19 C , Z = 82 , and k e = 8 . 98755 10 9 N m 2 / C 2 ....
View Full Document

## This note was uploaded on 02/17/2011 for the course PHY 303L taught by Professor Turner during the Spring '08 term at University of Texas at Austin.

### Page1 / 4

hw 5 - wilson (kw22588) HW5 Mackie (20224) 1 This print-out...

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

View Full Document
Ask a homework question - tutors are online