Physics (5th Edition)
5th Edition
ISBN: 9780321976444
Author: James S. Walker
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 11, Problem 82GP
Flats Versus Heels A woman might wear a pair of flat shoes to work during the day as in Figure 11-61 (a), but a pair of high heels Figure 11-61 (b), when going out for the evening. Assume that each foot supports half her weight. w = W/2 = 279 N, and that the forces exerted by the floor on her feet occur at the points A and B in both figures. Find the forces FA (point A) and FB (point B) for (a) flat shoes and (b) high heels. (c) How have the high heels changed the weight distribution between the woman’s heels and toes?
Figure 11-61 Problem 82
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
the figure shows a horizontal human arm lifting a dumbbell. the forearm is in equilibrium under the action of the weight w of the dumbbell, the tension t in the tendon connected to the biceps muscle, and the force e exerted on the forearm by the upper arm at the elbow joints. we neglect the weight of the forearm itself. (for clarity, the point a where the tendon is attached is drawn farther from the elbow than its actual position.) given the weight w and the angle between the tension force and the horizontal, find t and the two components of ē (three unknown scalar quantities in all)
A hiker, who weighs 659 N, is strolling through the woods and crosses a small horizontal bridge. The bridge is uniform, weighs 4280 N, and rests on two concrete supports, one on each end. He stops 1/5 of the way along the bridge. What is the magnitude of the force that a concrete support exerts on the bridge (a) at the near end and (b) at the far end?
. The forces exerted by the bicep muscle and acting on the elbow when a 12 kg barbell is being curledcan be modeled based on the diagram above. The bicep muscle can be treated as a vertical cable. Themass and length of the forearm are 2 kg and 32 cm, respectively. The center of mass of the forearm is adistance of 14 cm from the point P, while the bicep connects to the forearm at a point 4.5 cm from P.a) Determine the tension in bicep muscle and the force of the humerus acting downward on the elbowat point P. b) Assuming the tension in the bicep muscle continues to be oriented vertically, determinethe tension in the bicep muscle and the force acting at P after the barbell has been raised by an angleof 30 relative to the horizontal.
Chapter 11 Solutions
Physics (5th Edition)
Ch. 11.1 - A bicycle wheel is mounted on an axle, as shown in...Ch. 11.2 - Consider two objects with the following...Ch. 11.3 - A Physics sign is supported symmetrically by two...Ch. 11.4 - A mobile made from three piggy banks (A, B, C) is...Ch. 11.5 - Prob. 5EYUCh. 11.6 - Consider two objects with the following...Ch. 11.7 - Prob. 7EYUCh. 11.8 - In system 1, a torque of 20 N m acts through an...Ch. 11.9 - The angular velocity of the spinning bicycle wheel...Ch. 11 - Two forces produce the same torque. Does it follow...
Ch. 11 - A car pitches down in front when the brakes are...Ch. 11 - A tightrope walker uses a long pole to aid in...Ch. 11 - When a motorcycle accelerates rapidly from a stop...Ch. 11 - Give an example of a system in which the net...Ch. 11 - Give an example of a system in which the net force...Ch. 11 - Is the normal force exerted by the ground the same...Ch. 11 - Give two everyday examples of objects that are not...Ch. 11 - Give two everyday examples of objects that are in...Ch. 11 - Can an object have zero translational acceleration...Ch. 11 - Stars form when a large rotating cloud of gas...Ch. 11 - What purpose does the tail rotor on a helicopter...Ch. 11 - Is it possible to change the angular momentum of...Ch. 11 - Suppose a diver springs into the air with no...Ch. 11 - To tighten a spark plug, it is recommended that a...Ch. 11 - Pulling a Weed The gardening tool shown in Figure...Ch. 11 - A person slowly lowers a 3.6-kg crab trap over the...Ch. 11 - A squirrel-proof bird feeder has a lever that...Ch. 11 - At one position during its cycle, the foot pushes...Ch. 11 - BIO Predict/Calculate Force to Hold a Baseball A...Ch. 11 - At the local playground, a 21-kg child sits on the...Ch. 11 - Predict/Explain Consider the pulley-block systems...Ch. 11 - Suppose a torque rotates your body about one of...Ch. 11 - A torque of 0.97 N m is applied to a bicycle...Ch. 11 - When a ceiling fan rotating with an angular speed...Ch. 11 - When the play button is pressed, a CD accelerates...Ch. 11 - A person holds a ladder horizontally at its...Ch. 11 - A 0.180-kg wooden rod is 1.25 m long and pivots at...Ch. 11 - Predict/Calculate A wheel on a game show is given...Ch. 11 - The L-shaped object in Figure 11-41 consists of...Ch. 11 - The L-shaped object described in the previous...Ch. 11 - A motorcycle accelerates from rest, and both the...Ch. 11 - Predict/Calculate A torque of 13 N m is applied...Ch. 11 - Predict/Explain Suppose the person in Example...Ch. 11 - A string that passes over a pulley has a 0.321-kg...Ch. 11 - To loosen the lid on a jar of jam 7.6 cm in...Ch. 11 - BIO Predict/Calculate Referring to the person...Ch. 11 - Prob. 24PCECh. 11 - Prob. 25PCECh. 11 - Predict/Calculate A schoolyard teeter-totter with...Ch. 11 - A 0.122-kg remote control 23.0 cm long rests on a...Ch. 11 - Predict/Calculate A 0.16-kg meterstick is held...Ch. 11 - Prob. 29PCECh. 11 - A uniform metal rod, with a mass of 2.0 kg and a...Ch. 11 - Prob. 31PCECh. 11 - In Figure 11-46 two acrobats perform a balancing...Ch. 11 - BIO Forces in the Foot In Figure 11-47 we see the...Ch. 11 - A stick with a mass of 0.214 kg and a length of...Ch. 11 - Prob. 35PCECh. 11 - If the cat in Example 11-9 has a mass of 3.9 kg,...Ch. 11 - Prob. 37PCECh. 11 - Maximum Overhang Three identical, uniform books of...Ch. 11 - A baseball bat balances 71.1 cm from one end. If a...Ch. 11 - A 2.85-kg bucket is attached to a rope wrapped...Ch. 11 - A child exerts a tangential 53 4-N force on the...Ch. 11 - Predict/Calculate You pull downward with a force...Ch. 11 - One elevator arrangement includes the passenger...Ch. 11 - Atwood's Machine An Atwoods machine consists of...Ch. 11 - A 1.4-kg bicycle tire with a radius of 33 cm...Ch. 11 - Jogger 1 in Figure 11-51 has a mass of 65.3 kg and...Ch. 11 - Predict/Calculate Suppose jogger 3 in Figure 11-51...Ch. 11 - A torque of 0.12 N m is applied to an egg beater...Ch. 11 - A windmill has an initial angular momentum of 8500...Ch. 11 - Two gerbils run in place with a linear speed of...Ch. 11 - Predict/Explain A student rotates on a...Ch. 11 - A puck on a horizontal, frictionless surface is...Ch. 11 - A puck on a horizontal, frictionless surface is...Ch. 11 - As an ice skater begins a spin, his angular speed...Ch. 11 - A disk-shaped merry-go-round of radius 2.63 m and...Ch. 11 - A student sits at rest on a piano stool that can...Ch. 11 - Predict/Calculate A turntable with a moment of...Ch. 11 - A student on a piano stool rotates freely with an...Ch. 11 - Walking on a Merry-Go-Round A child of mass m...Ch. 11 - Predict/Explain Two spheres of equal mass and...Ch. 11 - Turning a doorknob through 0.25 of a revolution...Ch. 11 - A person exerts a tangential force of 36.1 N on...Ch. 11 - To prepare homemade ice cream a crank must be...Ch. 11 - Power of a Dental Drill A popular make of dental...Ch. 11 - For a home repair job you must turn the handle of...Ch. 11 - The L-shaped object in Figure 11-40 consists of...Ch. 11 - The rectangular object in Figure 11-41 consists of...Ch. 11 - Predict/Calculate A circular saw blade accelerates...Ch. 11 - CE A uniform disk stands upright on its edge, and...Ch. 11 - CE Consider the two rotating systems shown in...Ch. 11 - CE Predict/Explain A disk and a hoop (bicycle...Ch. 11 - CE A beetle sits at the nm of a turntable that is...Ch. 11 - After getting a drink of water a hamster jumps...Ch. 11 - A 47.0-kg uniform rod 4.25 m long is attached to a...Ch. 11 - Prob. 75GPCh. 11 - BIO The Masseter Muscle The masseter muscle, the...Ch. 11 - Exercising the Biceps You are designing exercise...Ch. 11 - Prob. 78GPCh. 11 - In Example 11-11, suppose the ladder is uniform,...Ch. 11 - When you arrive at Dukes Dude Ranch you are...Ch. 11 - Prob. 81GPCh. 11 - Flats Versus Heels A woman might wear a pair of...Ch. 11 - BIO A young girl sits at the edge of a dock by the...Ch. 11 - BIO Deltoid Muscle A crossing guard holds a STOP...Ch. 11 - BIO Triceps To determine the force a persons...Ch. 11 - Predict/Calculate Suppose partial melting of the...Ch. 11 - A bicycle wheel of radius R and mass M is at rest...Ch. 11 - A 0.101-kg yo-yo has an outer radius R that is...Ch. 11 - BIO Peak Pedaling Torque The downward force...Ch. 11 - A cylinder of mass m and radius r has a string...Ch. 11 - Bricks in Equilibrium Consider a system of four...Ch. 11 - BIO Correcting Torsiversion Torsiversion is a...Ch. 11 - BIO Correcting Torsiversion Torsiversion is a...Ch. 11 - BIO Correcting Torsiversion Torsiversion is a...Ch. 11 - BIO Correcting Torsiversion Torsiversion is a...Ch. 11 - Referring to Example 11-14 Suppose the mass of the...Ch. 11 - Prob. 97PPCh. 11 - Referring to Quick Example 11-22 Suppose the child...Ch. 11 - Referring to Quick Example 11-22 Suppose...
Additional Science Textbook Solutions
Find more solutions based on key concepts
A car moving at speed v undergoes a one-dimensional collision with an identical car initially at rest. The coll...
Essential University Physics (3rd Edition)
34.19 A person swimming 0.80 m below the surface of the water in a swimming pool looks at the diving board that...
University Physics with Modern Physics (14th Edition)
At which position(s), if any, does Star B rise and set?
Lecture- Tutorials for Introductory Astronomy
BIO Magnetic induction tomography (MIT) Magnetic induction tomography is an imaging method used in mineral, nat...
College Physics
Integrated Concepts A 35.0-kg dolphin decelerates from 12.0 to 7.50 m/s in 2.30 s to join another dolphin in pl...
College Physics
In Fig. 27.23a, take R = 2.5 k and 0 = 50 V. When the switch is closed, the current through the inductor rises ...
Essential University Physics: Volume 2 (3rd Edition)
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
- (a) What force should the woman in Figure 9.45 exert on the floor with each hand to do a push-up? Assume that she moves up at a constant speed. (b) The triceps muscle at the back of her upper arm has an effective lever arm of 1.75 cm, and she exerts force on the floor at a horizontal distance of 20.0 cm from the elbow joint. Calculate the magnitude of the force in each triceps muscle, and compare it to her weight. (c) How much work does she do if her center of mass rises 0.240 m? (d) What is her useful power output if she does 25 pushups in one minute?arrow_forwardThe Iron Cross When a gymnast weighing 750 N executes the iron cross as in Figure lN.91a, the primary muscles involved in supporting this position are the latissimus dorsi (lats") and the pectoralis major (pecs"). The rings exert an upward force on the aims and support the weight of the gymnast. The force exerted by the shoulder joint on the arm is labeled Fs, while the two muscles exert a total force Fw on the arm. Estimate the magnitude of the force Fw. Note that one ring supports half the weight of the gymnast, which is 375 N as indicated in Figure P8.91b. Assume that the force Fw acts at an angle of 45 below the horizontal at a distance of 4.0 cm from the shoulder joint In your estimate, take the distance from the shoulder joint to the hand to be L = 70 cm and ignore the weight of the arm.arrow_forwardBIO When a gymnast performing on the rings executes the iron cross, he maintains the position at rest shown in Figure P10.85a. In this maneuver, the gymnasts feet (not shown) are off the floor. The primary muscles involved in supporting this position are the latissimus dorsi (lats) and the pectoralis major (pecs). One of the rings exerts an upward fore Fh on a hand as shown in Figure P10.85b. The force Fs is exerted by the shoulder joint on the arm. The latissimus dorsi and pectoralis major muscles exert a total force Fm on the arm. (a) Using the information in the figure, find the magnitude of the force Fm. (b) Suppose an athlete in training cannot perform the iron cross but can hold a position similar to the figure in which the arms make a 45 angle with the horizontal rather than being horizontal. Why is this position easier for the athlete? Figure P10.85arrow_forward
- Unreasonable Results Suppose two children are using a uniform seesaw that is 3.00 m long and has its center of mass over the pivot. The first child has a mass of 30.0 kg and sits 1.40 m from the pivot. (a) Calculate where the second 18.0 kg child must sit to balance the seesaw. (b) What is unreasonable about the result? (c) Which premise is unreasonable, or which premises are inconsistent?arrow_forwardThe center of gravity of a 60-kg stroke patient is located at a 70-cm mark. If the patient is supported at 65 cm, where must an 80-g object be hung in order to attain equilibrium? The biceps muscle exerts a vertical force of 7090 N on the lower arm. Calculate (a.) The torque about the axis of rotation through the elbow joint if the biceps and lower arm are perpendicular to each other (b.) If the lower arm is 30 ° lower with respect to the horizontal. Assume that the muscle is attached 5.0 cm from the elbow.arrow_forwardQ#1(a): Two persons are playing on See-Saw as shown in figure below. Calculate the distance at which Person B must sit on to balance moment of force due to Person A on other side of pivot. Let you are Person A, having weight of (Your Student ID) N. (Hint: If your ID is 114-2020, then your weight would be 114 N)arrow_forward
- A man holds a 169-N ball in his hand, with the forearm horizontal (see the figure). He can support the ball in this position because of the flexor muscle force , which is applied perpendicular to the forearm. The forearm weighs 22.2 N and has a center of gravity as indicated. Find (a) the magnitude of and the (b) magnitude and (c) direction (as a positive angle counterclockwise from horizontal) of the force applied by the upper arm bone to the forearm at the elbow joint.arrow_forwardA man holds a 180-N ball in his hand, with the forearm horizontal (see the figure). He can support the ball in this position because of the flexor muscle force M→, which is applied perpendicular to the forearm. The forearm weighs 25.0 N and has a center of gravity as indicated. Find (a) the magnitude of M→ and the (b) magnitude and (c) direction (as a positive angle counterclockwise from horizontal) of the force applied by the upper arm bone to the forearm at the elbow joint.arrow_forwardA man holds a 192-N ball in his hand, with the forearm horizontal (see the figure). He can support the ball in this position because of the flexor muscle force M→, which is applied perpendicular to the forearm. The forearm weighs 24.2 N and has a center of gravity as indicated. Find (a) the magnitude of M→ and the (b) magnitude and (c) direction (as a positive angle counterclockwise from horizontal) of the force applied by the upper arm bone to the forearm at the elbow joint. Please show how the angle in c was foundarrow_forward
- A steel ladder of mass 40 kg and of length 20 m leans against a frictionless wall at a point 16 m above the ground. For safety purpose, the center of mass of the ladder is designed to be a quarter the way up. A 60 kg man is standing halfway up the ladder. (a) Calculate the reaction R from the ground and the angle θ it makes with the vertical. (b) If the man is to stand on the top of the ladder without slipping, find the minimum value for the coefficient of static friction between the ladder and the ground.arrow_forwardAn 8.31-m, 267-N uniform ladder rests against a smooth (frictionless) wall. The coefficient of static friction between the ladder and the ground is 0.582, and the ladder makes a 52.6∘∘ angle with the ground. A 901 N person is standing on the ladder a distance ?d from the bottom end of the ladder. (a) Draw a free-body diagram of the ladder. (b) How far up the ladder (distance ?d) can the person climb before the ladder begins to slip? Hint: Among other things, you may want to look at the sum of the torques about the point where the ladder touches the floor. Be careful with angles!arrow_forwardConsider a rigid steel beam of length L = 11.5 m and mass mb = 405 kg resting on two supports, one at each end. A worker of mass mw = 76 kg sits on the beam at a distance x from support A. Refer to the figure. a)When the worker sits at a distance x = 4.5 m from support A, calculate the force, in newtons, that support B must exert on the beam in order for it to remain at rest. Use g with three significant figures. b)The force exerted on the beam by support A is measured and found to be FA = 2180 N. At what distance x, in meters, from support A is the worker sitting now?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
College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781285737027
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Static Equilibrium: concept; Author: Jennifer Cash;https://www.youtube.com/watch?v=0BIgFKVnlBU;License: Standard YouTube License, CC-BY