QTest #7-solutions - tates at 62 rev / min. How Fast is it...

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

View Full Document Right Arrow Icon
Version 115/ABDAD – QTest #7 – Antoniewicz – (57420) 1 This print-out should have 3 questions. Multiple-choice questions may continue on the next column or page – fnd all choices beFore answering. 001 10.0 points The fgure below shows a rigid system which can rotate, with one mass three times the other. 3 . 5 kg 10 . 5 kg 0 . 6 m What is the moment oF inertia about an axis perpendicular to the paper and through the center oF mass? Consider the connecting rod to have negligible mass and treat the masses as point particles. 1. 3.267 2. 14.8838 3. 36.0375 4. 4.617 5. 0.945 6. 1.512 7. 9.8415 8. 6.09375 9. 0.6075 10. 16.416 Correct answer: 0 . 945 kg · m 2 . Explanation: Let : M = 3 . 5 kg , 3 M = 10 . 5 kg , and = 0 . 6 m . Let the origin coincide with the leFt mass M : X cm = m i r i m i = (3 M ) L M + 3 M = 3 4 L , so the moment oF inertia about the CM is I = s m i r 2 i = M p 3 4 L P 2 + 3 M p 1 4 L P 2 = 3 4 M L 2 = 3 4 (3 . 5 kg) (0 . 6 m) 2 = 0 . 945 kg · m 2 . 002 (part 1 of 2) 5.0 points Billy Dee notes that her Favorite record ro-
Background image of page 1

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

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: tates at 62 rev / min. How Fast is it rotating in rad/sec? 1. 5.34071 2. 6.07375 3. 3.14159 4. 3.97935 5. 6.17847 6. 3.76991 7. 4.29351 8. 4.71239 9. 5.55015 10. 6.49262 Correct answer: 6 . 49262 rad / s. Explanation: Let : = 62 rev / min . (62 rev / min) 2 1 rev 1 min 60 s = 6 . 49262 rad / s . 003 (part 2 of 2) 5.0 points At what speed does the point on the record touching the stylus (needle) move when the stylus (needle) is 9 . 9 cm From the center? 1. 58.4336 2. 64.277 3. 25.6563 4. 43.9823 5. 33.4684 6. 36.4425 7. 38.9557 8. 47.5742 Version 115/ABDAD QTest #7 Antoniewicz (57420) 2 9. 27.8555 10. 46.4642 Correct answer: 64 . 277 cm / s. Explanation: Let : r = 9 . 9 cm . v = r = (9 . 9 cm) (6 . 49262 rad / s) = 64 . 277 cm / s ....
View Full Document

This note was uploaded on 05/02/2011 for the course PHY 303K taught by Professor Turner during the Spring '08 term at University of Texas at Austin.

Page1 / 2

QTest #7-solutions - tates at 62 rev / min. How Fast is it...

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