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 principalsupporting 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 personbending 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 theway up the spine, maintains the position of the back. The angle between the spine and this muscle is 12.0⁰.Back muscleR₂T 12.0°1TRxPivotaWbWo..(a).Find the tension in the back muscle.1.114Enter a number. differs from the correct answer by more than 10%. Double check your calculations. kN(b) Find the compressional force in the spine. (Enter the magnitude.)1.09Your response differs from the correct answer by more than 10%. Double check your calculations. kN

Answered: Image /qna-images/answer/8205b14e-188e-44fb-8abb-e41ba8f662e2.jpg

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 W. 195-N object. The spine and upper body are represented as a uniform horizontal rod of weight W=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 Pivot R R₂ b T 12.0° W₂ W₂ ↑ (a).Find the tension in the back muscle. 1.114 x Enter a number. differs from the correct answer by more than 10%. Double check your calculations. kN (b) Find the compressional force in the spine. (Enter the magnitude.) 1.09 X Your response differs from the correct answer by more than 10%. Double check calculations, KN

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 W. 195-N object. The spine and upper body are represented as a uniform horizontal rod of weight W=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 Pivot R R₂ b T 12.0° W₂ W₂ ↑ (a).Find the tension in the back muscle. 1.114 x Enter a number. differs from the correct answer by more than 10%. Double check your calculations. kN (b) Find the compressional force in the spine. (Enter the magnitude.) 1.09 X Your response differs from the correct answer by more than 10%. Double check calculations, KN

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)...

See similar textbooks

Similar questions

The bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass of 2.35 kg and a length of 0.445 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 6.15 kg so that her forearm remains motionless, what is the force F exerted by the biceps muscle? 5 Humerus. F= Elbow. Biceps muscle Radius Ulna Hand N
3. A person holds a 10.0 kg lead ball in his hand, a distance of 32.0 cm from the elbow joint, as shown. The biceps, attached at a distance of 2.5 cm from the elbow, exerts an upward force on the forearm. Consider the forearm and hand to be a uniform rod with a mass of 1.50 kg. Calculate the force provided by the biceps muscle in order to hold the arm horizontally as shown. Use the elbow joint as the pivot point. Biceps 32 cm 2.5 cm
The bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass of 2.35 kg and a length of 0.445 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 6.15 kg so that her forearm remains motionless, what is the force exerted by the biceps muscle
Bart ( whose mass is 31.1 kg) and Milhouse (whose mass is 20.4 kg) sit balanced on a teeter -totter that has its pivot point at its exact center . If the two boys are separated by a distance of 2.52 m, at what distance (in m) from the pivot point must Milhouse be sitting at in order to maintain the balance? Explain how you solved the problem involving children balancing on a teeter-totter. Be sure to state what your known and unknown quantities are, what concepts were applied, and what equations were used!
A hungry bear weighing 85.0 kg walks out on a beam in an attempt to retrieve a basket of food hanging at the end of the beam. The beam is uniform, has a mass of 20.0 kg, is 8.00 m long, and pivoted at the wall; the basket weighs 10.0 kg. If the wire can withstand a maximum tension of 900 N, what is the maximum distance that the bear can walk before the wire breaks? ←x 60.0⁰ Goodies
How do I find FM and FJ correctly?
A 3m long weightless beam is supported at each end by cables. A painter weighing 900N stands 1m from the left cable. Calculate the tension in each cable. Please provide complete solution with figures
A person places his hand palm downward on a scale and pushes down on the scale until it reads (8.31x10^1) N. The triceps muscle is responsible for this arm extension force. Find the force (in N) exerted by the triceps muscle. The bottom of the triceps muscle is 2.50 cm to the left of the elbow joint, and the palm is pushing at approximately 35.0 cm to the right of the elbow joint. (please ignore the number 96 shown in the scale). Give your answer with three significant figures.
.As a part of his daily workout routine, he lifts 10-kg dumbbells on each hand. His hands and forearms weigh 4 kg each. If the length of each of his forearms and hands are 0.5 m, determine the force exerted by his muscles? Assume that the center of gravity of the forearms are in the middle.
A new art exhibit featuring mobile works is going up in the Holland, MI, area. One piece is shown in the figure. The 140-N uniform beam is pinned to the ground by a pivot. The beam is supported by a cable (attached to the center of the beam) to allow for each of the shoes to hang freely. Each individual shoe has a weight of 9.5-N. 1.If one shoe is attached two-fifths of the way up the beam and another shoe is attached and three-fifths of the way up the beam, with θc = 19.5° and θb = 33.5° as shown in the figure, what is the tension in the cable, in newtons?
What is the student’s weight?
Why is a tapered water glass with a narrow base easier to tip over than a glass with straight sides? Does it matter whether the glass is full or empty?