# 2-5 - Create assignment 00224 Homework 5 Feb 28 at 6:39 pm...

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: Create assignment, 00224, Homework 5, Feb 28 at 6:39 pm 1 This print-out should have 9 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. The due time is Central time. Lengthening a Wire 02 27:03, trigonometry, numeric, > 1 min, nor- mal. 001 A wire with a resistance R is lengthened to 1 . 25 times its original length by pulling it through a small hole. Find the resistance of the wire after it is stretched. Correct answer: 1 . 5625 R . Explanation: Let : ‘ = 1 . 25 ‘ . The volume V of the wire is given by V = ‘ A, where ‘ is the length of the wire and A is the cross-sectional area. When the wire is stretched to a length ‘ , the volume will re- main the same. The new cross-sectional area is then, ‘ A = ‘ A A = ‘ A ‘ = ‘ A 1 . 25 ‘ = A 1 . 25 . The resistance of a conductor of resistivity ρ is given by R = ρ ‘ A , so R R = ρ ‘ A ρ ‘ A = ‘ A ‘ A = (1 . 25 ‘ ) A ‘ µ A 1 . 25 ¶ = (1 . 25) 2 . Thus R = (1 . 25) 2 R = 1 . 5625 R . keywords: Serway CP 17 64 27:03, trigonometry, numeric, > 1 min, nor- mal....
View Full Document

{[ snackBarMessage ]}

### Page1 / 3

2-5 - Create assignment 00224 Homework 5 Feb 28 at 6:39 pm...

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

View Full Document
Ask a homework question - tutors are online