Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo
College Physics for AP® Courses

Chapter 10

College Physics for AP® CoursesChapter 10

Problems & Exercises

1.

ω = 0 . 737 rev/s ω = 0 . 737 rev/s size 12{ω= {underline {0 "." "737 rev/s"}} } {}

3.

(a) 0.26 rad/s20.26 rad/s2 size 12{ - 0 "." "26 rad/s" rSup { size 8{2} } } {}

(b) 27rev27rev size 12{"27"`"rev"} {}

5.

(a) 80 rad/s280 rad/s2 size 12{80 rad/s" rSup { size 8{2} } } {}

(b) 1.0 rev

7.

(a) 45.7 s

(b) 116 rev

9.

a) 600 rad/s2600 rad/s2 size 12{ {underline {6"00 rad/s" rSup { size 8{2} } }} } {}

b) 450 rad/s

c) 21.0 m/s

10.

(a) 0.338 s

(b) 0.0403 rev

(c) 0.313 s

12.

0.50 kg m 2 0.50 kg m 2 size 12{5 "." "00"``"kg" cdot m rSup { size 8{2} } } {}

14.

(a) 50.4 Nm50.4 Nm

(b) 17.1 rad/s217.1 rad/s2 size 12{"17" "." 1``"rad/s" rSup { size 8{2} } } {}

(c) 17.0 rad/s217.0 rad/s2 size 12{"17" "." 0``"rad/s" rSup { size 8{2} } } {}

16.

3 . 96 × 10 18 s 3 . 96 × 10 18 s size 12{3 "." "96" times "10" rSup { size 8{"18"} } `s} {}

or 1.26 × 10 11 y 1.26 × 10 11 y size 12{1 "." "26" times "10" rSup { size 8{"11"} } `y} {}

18.

I end = I center + m l 2 2 Thus, I center = I end 1 4 ml 2 = 1 3 ml 2 1 4 ml 2 = 1 12 ml 2 I end = I center + m l 2 2 Thus, I center = I end 1 4 ml 2 = 1 3 ml 2 1 4 ml 2 = 1 12 ml 2

19.

(a) 2.0 ms

(b) The time interval is too short.

(c) The moment of inertia is much too small, by one to two orders of magnitude. A torque of 500 Nm500 Nm size 12{"500 N" cdot m} {} is reasonable.

20.

(a) 17,500 rpm

(b) This angular velocity is very high for a disk of this size and mass. The radial acceleration at the edge of the disk is > 50,000 gs.

(c) Flywheel mass and radius should both be much greater, allowing for a lower spin rate (angular velocity).

21.

(a) 185 J

(b) 0.0785 rev

(c) W=9.81 NW=9.81 N size 12{W= {underline {9 "." "81 N"}} } {}

23.

(a) 2.57×1029 J2.57×1029 J size 12{9 "." "736" times "10" rSup { size 8{"37"} } " kg" "." m rSup { size 8{2} } } {}

(b) KErot=2.65×1033 JKErot=2.65×1033 J size 12{"KE" rSub { size 8{"tot"} } = {underline {2 "." "65" times "10" rSup { size 8{"33"} } " J"}} } {}

25.

KE rot = 434 J KE rot = 434 J size 12{ ital "KE" rSub { size 8{ ital "rot"} } = {"434 J"} } {}

27.

(a) 128 rad/s128 rad/s size 12{ {underline {"128 rad/s"}} } {}

(b) 19.9 m19.9 m

29.

(a) 10.4 rad/s210.4 rad/s2 size 12{α= {underline {"19" "." "5 rad/s" rSup { size 8{2} } }} } {}

(b) net W=6.11 J net W=6.11 J size 12{" net W"= {underline {6 "." "31 J"}} } {}

34.

(a) 1.49 kJ

(b) 2.52×104 N2.52×104 N size 12{I= {underline {9 "." "61" times "10" rSup { size 8{3} } " N"}} } {}

36.

(a) 2.66×1040kgm2/s2.66×1040kgm2/s size 12{2 "." "66" times "10" rSup { size 8{"40"} } `"kg" cdot m rSup { size 8{2} } "/s"} {}

(b) 7.07×1033kgm2/s7.07×1033kgm2/s size 12{7 "." "07" times "10" rSup { size 8{"33"} } `"kg" cdot m rSup { size 8{2} } "/s"} {}

The angular momentum of the Earth in its orbit around the Sun is 3.77×1063.77×106 size 12{3 "." "76" times "10" rSup { size 8{6} } } {} times larger than the angular momentum of the Earth around its axis.

38.

22 . 5 kg m 2 /s 22 . 5 kg m 2 /s size 12{"22" "." "5 kg" cdot m rSup { size 8{2} } "/s"} {}

40.

25.3 rpm

43.

(a) 0.156 rad/s0.156 rad/s

(b) 1.17×102 J1.17×102 J size 12{1 "." "17" times "10" rSup { size 8{ - 2} } " J"} {}

(c) 0.188 kgm/s0.188 kgm/s size 12{0 "." "188 kg" cdot "m/s"} {}

45.

(a) 3.13 rad/s

(b) Initial KE = 438 J, final KE = 438 J

47.

(a) 1.70 rad/s

(b) Initial KE = 22.5 J, final KE = 2.04 J

(c) 1.50 kgm/s1.50 kgm/s size 12{1 "." "50 kg" cdot "m/s"} {}

48.

(a) 5.64×1033kgm2/s5.64×1033kgm2/s size 12{5 "." "65" times "10" rSup { size 8{"33"} } `"kg" "." m rSup { size 8{2} } "/s"} {}

(b) 1.39×1022Nm1.39×1022Nm size 12{1 "." "39" times "10" rSup { size 8{"22"} } `N cdot m} {}

(c) 2.17×1015N2.17×1015N size 12{2 "." "18" times "10" rSup { size 8{"15"} } `N} {}

Test Prep for AP® Courses

1.

(b)

3.

(d)

5.

(d)

You are given a thin rod of length 1.0 m and mass 2.0 kg, a small lead weight of 0.50 kg, and a not-so-small lead weight of 1.0 kg. The rod has three holes, one in each end and one through the middle, which may either hold a pivot point or one of the small lead weights.

7.

(a)

9.

(c)

11.

(a)

13.

(a)

15.

(b)

17.

(c)

19.

(b)

21.

(b)

23.

(c)

25.

(d)

27.

A door on hinges is a rotational system. When you push or pull on the door handle, the angular momentum of the system changes. If a weight is hung on the door handle, then pushing on the door with the same force will cause a different increase in angular momentum. If you push or pull near the hinges with the same force, the resulting angular momentum of the system will also be different.

29.

Since the globe is stationary to start with,

τ= ΔL Δt τ= ΔL Δt

τΔt=ΔL τΔt=ΔL

By substituting,

120 N•m • 1.2 s = 144 N•m•s.

The angular momentum of the globe after 1.2 s is 144 N•m•s.

Order a print copy

As an Amazon Associate we earn from qualifying purchases.

Citation/Attribution

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at https://openstax.org/books/college-physics-ap-courses/pages/1-connection-for-ap-r-courses
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at https://openstax.org/books/college-physics-ap-courses/pages/1-connection-for-ap-r-courses
Citation information

© Mar 3, 2022 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.