Homework 9 Solutions

Homework 9 Solutions - hÝ × ic×ÙÑÑ eÖ8ÓÑ eÛ Ó...

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: hÝ × ic×ÙÑÑ eÖ8ÓÑ eÛ Ó Ök# 9 Ó ÐÙ Ø iÓÒ ×bÝ iÑC a ÐÐahaÒ § 9 Problem 15 ( a ): The flywheel turns 200 revolutions in 30.0 s, which is an average rate of 400 rpm. This is the average , which is one half of the initial plus the final. As the initial rate was 500 rpm, the final rate must be 300 rpm. ( b ): After 30 seconds the flywheel lost 200 rpm. At this rate, it would take 75 s for it to lose the whole 500 rpm and come to a stop. During this time the average rate is 250 rpm, and as it takes 1.25 minutes, this comes to 313 complete revolutions. § 9 Problem 34 ( a ): We ignore the mass of the rods. We find mr 2 for each mass and add them up. For an axis through the center of the square and perpendicular to it, each mass is a distance 0 . 200 √ 2 m from the axis. Thus the moment of inertia is I = 4(0 . 200 kg) bracketleftbig (0 . 200 m) 2 + (0 . 200 m) 2 bracketrightbig = 0 . 064 kg m 2 . ( b ): Now each mass is a distance 0.200 m from the axis, so I = 4(0 . 200 kg)(0 . 200 m) 2 = 0 . 032 kg m 2 . ( c ): Now two of the masses have a distance of 0 from the axis, and two have a distance of 0 . 200 √ 2 m from the axis. Thus I = 2(0 . 200 kg) bracketleftbig (0 . 200 m) 2 + (0 . 200 m) 2 bracketrightbig = 0 . 032 kg m 2 . § 9 Problem 41: The mass of the inner disc is ρπr 2 = 23600 g = 23 . 6 kg ....
View Full Document

This note was uploaded on 07/12/2008 for the course PHY 121 taught by Professor Chamberlin during the Summer '08 term at ASU.

Page1 / 3

Homework 9 Solutions - hÝ × ic×ÙÑÑ eÖ8ÓÑ eÛ Ó...

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