COLLEGE PHYSICS
2nd Edition
ISBN: 9781711470832
Author: OpenStax
Publisher: XANEDU
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 9, Problem 32PE
To determine
(a)
The force exerted by the muscles.
To determine
(b)
The force exerted by the pivot on the head.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Even when the head is held erect, as in the figure below, its center of mass is not directly over the principal point of support (the atlanto-occipital joint).
The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class.
(a)
Calculate the force (in N) exerted by these muscles. (Assume
w = 48 N, r1 = 4.8 cm, and r2 = 2.9 cm.)
magnitude Ndirection ---Select--- upward downward to the left to the right
(b)
What is the force (in N) exerted by the pivot on the head?
magnitude Ndirection ---Select--- upward downward to the left to the right
Even when the head is held erect, as in Figure shown, its center of mass is not directly over the principal point of support (the atlanto-occipital joint). The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. Calculate the force exerted by these muscles using the information in the figure.
Even when the head is held erect, as shown in the figure, its
center of mass is not directly over the principal point of
support (the atlanto-occipital joint, Point A). The muscles at
the back of the neck should, therefore, exert a force to keep
the head erect. That is why your head falls forward when you
fall asleep in the class.
If the head weighs 43 N, calculate the force exerted by the
muscles FM using the information in the figure. Assume that
x1 = 4.9 cm, x2 = 2.7 cm, and F = 43 N.
W
FM =
A
M
What is the force F¡ exerted by the pivot on the head?
F =
N
Chapter 9 Solutions
COLLEGE PHYSICS
Ch. 9 - What can you say about the velocity of a moving...Ch. 9 - Under what conditions can a rotating body be in...Ch. 9 - What three factors affect the torque created by a...Ch. 9 - A wrecking ball is being used to knock down a...Ch. 9 - Mechanics put a length of Pipe over the handle of...Ch. 9 - Prob. 6CQCh. 9 - Explain the need for tall towers on a suspension...Ch. 9 - When visiting some countries, you may see a person...Ch. 9 - Prob. 9CQCh. 9 - Prob. 10CQ
Ch. 9 - Why are the forces exerted on the outside world by...Ch. 9 - Explain why the forces in our joints are several...Ch. 9 - Why are the forces exerted on the outside world by...Ch. 9 - Explain why the forces in our joints are several...Ch. 9 - Certain of dinosaurs were bipedal (walked on two...Ch. 9 - Swimmers and athletes during competition need to...Ch. 9 - If the maximum force the biceps muscle can exert...Ch. 9 - Suppose the biceps muscle was attached through...Ch. 9 - Explain one of the reasons why pregnant women...Ch. 9 - (a) When opening a door, you push on it...Ch. 9 - When tightening a bolt, you push perpendicularly...Ch. 9 - Two children push on opposite sides of a door...Ch. 9 - Use the second condition for equilibrium (net =0 )...Ch. 9 - Repeat the seesaw problem in Example 9.1 with the...Ch. 9 - Prob. 6PECh. 9 - Two children of mass 20.0 kg and 30.0 kg sit...Ch. 9 - Prob. 8PECh. 9 - A person carries a plank of wood 2.00 m long with...Ch. 9 - Prob. 10PECh. 9 - Prob. 11PECh. 9 - Prob. 12PECh. 9 - Prob. 13PECh. 9 - Prob. 14PECh. 9 - Prob. 15PECh. 9 - Prob. 16PECh. 9 - To get up on the roof, a person (mass 70.0 kg)...Ch. 9 - Prob. 18PECh. 9 - Prob. 19PECh. 9 - Suppose you needed to raise a 250-kg mower a...Ch. 9 - Prob. 21PECh. 9 - Prob. 22PECh. 9 - Prob. 23PECh. 9 - Prob. 24PECh. 9 - Prob. 25PECh. 9 - Prob. 26PECh. 9 - Prob. 27PECh. 9 - Prob. 28PECh. 9 - Prob. 29PECh. 9 - Prob. 30PECh. 9 - Prob. 31PECh. 9 - Prob. 32PECh. 9 - Prob. 33PECh. 9 - Prob. 34PECh. 9 - Prob. 35PECh. 9 - Integrated Concepts Suppose we replace the 4.0-kg...Ch. 9 - Prob. 37PECh. 9 - You have just planted a sturdy 2-m-tall palm tree...Ch. 9 - Unreasonable Results Suppose two children are...Ch. 9 - Construct Your Own Problem Consider a method for...Ch. 9 - Prob. 1TPCh. 9 - Prob. 2TPCh. 9 - Prob. 3TPCh. 9 - Prob. 4TPCh. 9 - Prob. 5TPCh. 9 - Prob. 6TPCh. 9 - Prob. 7TPCh. 9 - Prob. 8TPCh. 9 - Prob. 9TPCh. 9 - Prob. 10TPCh. 9 - Prob. 11TP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Even when the head is held erect, as shown in the figure, its center of mass is not directly over the principal point of support (the atlanto-occipital joint, Point A). The muscles at the back of the neck should, therefore, exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. If the head weighs 43 N, calculate the force exerted by the muscles FM using the information in the figure. Assume that x1 = 5.1 cm, x2 = 2.7 cm, and |Fw = 43 N. N What is the force Fj exerted by the pivot on the head? F; = N Question Credit: OpenStax College Physicsarrow_forwardEven when the head is held erect, as shown in the figure, its center of mass is not directly over the principal point of support (the atlanto-occipital joint, Point A). The muscles at the back of the neck should, therefore, exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. If the head weighs 55 N, calculate the force exerted by the muscles FM using the information in the figure. Assume that 5.1 cm, x2 2.5 cm, and Fw = 55 N. X1 = -26.96 A F N M = Incorrect M What is the force Fj exerted by the pivot on the head? -81.96 Fj = N Incorrectarrow_forwardEven when the head is held erect, as shown in the figure, its center of mass is not directly over the principal point of support (the atlanto-occipital joint, Point A). The muscles at the back of the neck should, therefore, exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. If the head weighs 55 N, calculate the force exerted by the muscles FM using the information in the figure. Assume that x1 = 5.1 cm, x2 = 1.9 cm, and |Fw = 55 N. W EM = FM A N M What is the force Fj exerted by the pivot on the head? F, N = Question Credit: OpenStax College Physicsarrow_forward
- Even when the head is held erect, as shown in the figure, its center of mass is not directly over the principal point of support (the atlanto-occipital joint, Point A). The muscles at the back of the neck should, therefore, exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. If the head weighs 55 N, calculate the force exerted by the muscles FM using the information in the figure. Assume that x1 = 5.1 cm, x2 = 1.9 cm, and Fw = 55 N. FM = N What is the force Fj exerted by the pivot on the head? F = Narrow_forwardEven when the head is held erect, as shown in the figure, its center of mass is not directly over the principal point of support (the atlanto-occipital joint, Point A). The muscles at the back of the neck should, therefore, exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. If the head weighs 51 N, calculate the force exerted by the muscles Fm using the information in the figure. Assume that x1=5.3 cm, x2 = 2.5 cm, and |Fw|= 51 N. What is the force Fj exerted by the pivot on the head? Fj=arrow_forwardEven when the head is held erect, as in the figure below, its center of mass is not directly over the principal point of support (the atlanto-occipital joint). The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. Calculate the force (in N) exerted by these muscles. (Assume w = 55 N, r1 = 4.8 cm, and r2 = 2.9 cm.) magnitude N direction (upward, downward, to the left, or to the right) What is the force (in N) exerted by the pivot on the head? magnitude N direction (upward, downward, to the left, or to the right)arrow_forward
- You can find the center of gravity of a meter stick by resting it horizontally on your two index fingers, and then slowly drawing your fingers together. First the meter stick will slip on one finger, and then on the other, but eventually the fingers meet at the CG. Why does this work?arrow_forwardEven when the head is held erect, as shown in the figure, its center of mass is not directly over the principal point of support (the atlanto-occipital joint). The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head falls forward when you fall asleep in class. Part (a) If the head has a weight of 48.3 N, calculate the force in units of newtons exerted by these muscles using the information in the figure. Part (b) What is the force in newtons exerted by the pivot on the head?arrow_forwardA person bending forward to lift a load "with his back" (Figure a) rather than with his knees" can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. To see the magnitude of the forces involved, and to understand why back problems are common among humans, consider the model shown in Figure b, of a person bending forward to lift a W-195-N object. The spine and upper body are represented as a uniform horizontal rod of weight W-295 N pivoted at the base of the spine. The erector spinalls muscle, attached at a point two-thirds of the way up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0° Back muscle Pivot R₂ T120 T W W₂ 0 (a) Find the tension in the back muscle. KN D (b) Find the compressional force in the spine. (Enter the magnitude.) KNarrow_forward
- A person bending forward to lift a load "with his back" (Figure a) rather than "with his knees" can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. To see the magnitude of the forces involved, and to understand why back problems are common among humans, consider the model shown in Figure b, of a person bending forward to lift a Wo = 195-N object. The spine and upper body are represented as a uniform horizontal rod of weight W₁ = 305 N pivoted at the base of the spine. The erector spinalis muscle, attached at a point two-thirds of the way up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0⁰. Back muscle R₂ T 12.0° 1T Rx Pivot a Wb Wo ..(a).Find the tension in the back muscle. 1.114 Enter a number. differs from the correct answer by more than 10%. Double check your calculations. kN…arrow_forwardA person bending forward to lift a load "with his back" (Figure a) rather than "with his knees" can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. To see the magnitude of the forces involved, and to understand why back problems are common among humans, consider the model shown in Figure b, of a person bending forward to lift a Wo = 210–N object. The spine and upper body are represented as a uniform horizontal rod of weight Wb = 325 N pivoted at the base of the spine. The erector spinalis muscle, attached at a point two-thirds of the way up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0arrow_forwardA person bending forward to lift a load "with his back" (Figure a) rather than "with his knees" can be injured by large forces exerted on the muscles and vertebrae. The spine pivots mainly at the fifth lumbar vertebra, with the principal supporting force provided by the erector spinalis muscle in the back. To see the magnitude of the forces involved, and to understand why back problems are common among humans, consider the model shown in Figure b, of a person bending forward to lift a W 170-N object. The spine and upper body are represented as a uniform horizontal rod of weight W = 355 N pivoted at the base of the spine. The erector spinalis muscle, attached at a point two-thirds of the way up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0°. Back muscle Pivot = a R₂ T 12.0° Rx Wb Wo (i) (a) Find the tension in the back muscle. 1.114 Your response differs from the correct answer by more than 10%. Double check your calculations. kN (b)…arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
University Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSON
Introduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Lecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON