Effective location 30° of erector spinae muscles Center of gravity of head and arms 12° Center of gravity of upper torso Pivot FIGURE P8.68

College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
icon
Related questions
Question

When you bend over, a series of large muscles, the erector spinae, pull on your spine to hold you up. Figure shows a simplified model of the spine as a rod of length L that pivots at its lower end. In this model, the center of gravity of the 320 N weight of the upper torso is at the center of the spine. The 160 N weight of the head and arms acts at the top of the spine. The erector spinae muscles are modeled as a single muscle that acts at an 12° angle to the spine. Suppose the person shown bends over to an angle of 30° from the horizontal.

a. What is the tension in the erector muscle? Hint: Align your x-axis with the axis of the spine.
b. A force from the pelvic girdle acts on the base of the spine. What is the component of this force in the direction of the spine? (This large force is the cause of many back injuries).

Effective location
30°
of erector spinae
muscles
Center of gravity
of head and arms
12°
Center of gravity
of upper torso
Pivot
FIGURE P8.68
Transcribed Image Text:Effective location 30° of erector spinae muscles Center of gravity of head and arms 12° Center of gravity of upper torso Pivot FIGURE P8.68
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps

Blurred answer
Knowledge Booster
Center of gravity of a system
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
  • SEE MORE QUESTIONS
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
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…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON

Expert Answers to Latest Homework Questions

Q: answer must be in table format or i will give down vote
Q: answer must be in proper format if that ok i will give upvote
Q: 15. Draw the major organic product for each of the following reactions. Write NR if a reaction will…
Q: Don't use chat gpt It Chatgpt means downvote
Q: answer must be in proper format or i will give down vote
Q: The following salaried employees of Mountain Stone Brewery in Fort Collins, Colorado, are paid…
Q: Current Attempt in Progress The following is a comparative SFP position and income statement for…
Q: Bill Clinton reportedly was paid $9.0 million to write his book My Life. The book took three years…
Q: Samy Inc. operated at its normal capacity during the current year, producing 75,000 units of its…
Q: Don't use chatgpt it chat gpt means downvote solve correctly
Q: 6 ft D -4 ft- -4 ft- B | Determine the normal force at point b using method of section if w =…
Q: Draw a curved arrow mechanism for the following reaction. Add/Remove step X H H B H BH₂
Q: You purchase an RV by making a down payment of $10,500. The terms of your finance agreement have an…
Q: 8. Which of the following cannot be listed as the objective of this experiment? Study the refraction…
Q: The aquation of tris(1,10-phenanthroline)iron(II) in acid solution takes place according to the…
Q: < :0: NaNH2 Drawing
Q: You work in the mergers and acquisitions department of a large conglomerate who is looking to invest…
Q: In public health, we often struggle for funding. Understanding which health challenges are…
Q: What are the typical steps involved in EHR vendor selection in an EHR enterprise/hospital or…
Q: Assume that in one department of your organization, the voluntary turnover rate is double that of…
Q: In the complex landscape of business decisions, the question of when to drop an unprofitable…