College Physics: A Strategic Approach (4th Edition)
4th Edition
ISBN: 9780134609034
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 7, Problem 67GP
A 70 kg man’s arm, including the hand, can be modeled as a 75-cm-long uniform cylinder with a mass of 3.5 kg. In raising both his arms, from hanging down to straight up, by how much does he raise his center of gravity?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A 75 kg man's arm, including the hand, can be modeled as a 79-cm-long uniform cylinder with a mass of 3.7 kg.
In raising both his arms, from hanging down to straight up, by how much does he raise his center of gravity?
Stand with your heels and back against a wall and try to bend over and touch your toes. You’ll find that you have to stand away from the wall to do so without toppling over. Compare the minimum distance of your heels from the wall with the distance for a friend of the opposite sex. Who can touch their toes with their heels nearer to the wall: men or women? On the average and in proportion to height, which sex has the lower center of gravity?
The femur of a human leg (mass 10 kg, length 0.9 m) is in
traction, as shown in the figure. The center of gravity of the
leg is one-third of the distance from the pelvis to the
bottom of the foot. Two objects, with masses mj and m2,
m,
are hung at the ends of the leg using pulleys to provide
upward support. A third object of 8 kg is hung to provide
tension along the leg. The body provides tension as well.
body
Write a mathematical relationship relating mi to m2 in
terms of m2 and numerical coefficients.
8 kg
mj =
m- m2
Incorrect
Is the expression for m1 valid for more than one pair of
values of mj and m2?
yes
no
Incorrect
Suppose the tension force due to mj is now applied at the
leg's center of mass.
Write a new expression relating m, to m2 in terms of m2,
numerical coefficients, and given values. If you use a given
value in your equation, enter it as a number without units.
Chapter 7 Solutions
College Physics: A Strategic Approach (4th Edition)
Ch. 7 - The batter in a baseball game hits a home run. As...Ch. 7 - Viewed from somewhere in space above the north...Ch. 7 - Figure Q7.3 shows four pulleys, each with a heavy...Ch. 7 - If you are using a wrench to loosen a very...Ch. 7 - Prob. 5CQCh. 7 - Prob. 6CQCh. 7 - Prob. 7CQCh. 7 - A screwdriver with a very thick handle requires...Ch. 7 - If you have ever driven a truck, you likely found...Ch. 7 - A student gives a steady push to a ball at the end...
Ch. 7 - Prob. 11CQCh. 7 - If you grasp a hammer by its lightweight handle...Ch. 7 - Prob. 13CQCh. 7 - Prob. 15CQCh. 7 - The moment of inertia of a uniform rod about an...Ch. 7 - Prob. 17CQCh. 7 - With care, its possible to walk on top of a barrel...Ch. 7 - A nut needs to be tightened with a wrench. Which...Ch. 7 - Prob. 20MCQCh. 7 - Prob. 21MCQCh. 7 - Prob. 22MCQCh. 7 - Prob. 23MCQCh. 7 - A typical compact disk has a mass of 15 g and a...Ch. 7 - Two horizontal rods are each held up by vertical...Ch. 7 - Prob. 26MCQCh. 7 - Questions 25 through 27 concern a classic...Ch. 7 - Questions 25 through 27 concern a classic...Ch. 7 - Questions 25 through 27 concern a classic...Ch. 7 - What is the angular position in radians of the...Ch. 7 - A child on a merry-go-round takes 3.0 s to go...Ch. 7 - What is the angular speed of the tip of the minute...Ch. 7 - An old-fashioned vinyl record rotates on a...Ch. 7 - The earths radius is about 4000 miles. Kampala,...Ch. 7 - Prob. 6PCh. 7 - A turntable rotates counterclockwise at 78 rpm. A...Ch. 7 - Prob. 8PCh. 7 - Prob. 9PCh. 7 - Prob. 10PCh. 7 - The 1.00-cm-long second hand on a watch rotates...Ch. 7 - The earths radius is 6.37 106 m; it rotates once...Ch. 7 - To throw a discus, the thrower holds it with a...Ch. 7 - Prob. 14PCh. 7 - A computer hard disk starts from rest, then speeds...Ch. 7 - Prob. 16PCh. 7 - The crankshaft in a race car goes from rest to...Ch. 7 - Reconsider the situation in Example 7.10. If Luis...Ch. 7 - Prob. 19PCh. 7 - Prob. 20PCh. 7 - What is the net torque about the axle on the...Ch. 7 - The tune-up specifications of a car call for the...Ch. 7 - In Figure P7.22, force F2, acts half as far from...Ch. 7 - A professors office door is 0.91 m wide, 2.0 m...Ch. 7 - What is the net torque on the bar shown in Figure...Ch. 7 - Prob. 26PCh. 7 - Prob. 27PCh. 7 - Prob. 28PCh. 7 - What is the net torque on the bar shown in Figure...Ch. 7 - Prob. 30PCh. 7 - The 2.0 kg, uniform, horizontal rod in Figure...Ch. 7 - A 4.00-m-long, 500 kg steel beam extends...Ch. 7 - An athlete at the gym holds a 3.0 kg steel ball in...Ch. 7 - The 2.0-m-long, 15 kg beam in Figure P7.34 is...Ch. 7 - Prob. 35PCh. 7 - Hold your arm outstretched so that it is...Ch. 7 - Prob. 37PCh. 7 - Prob. 38PCh. 7 - A regulation table tennis ball is a thin spherical...Ch. 7 - Prob. 40PCh. 7 - A solid cylinder with a radius of 4.0 cm has the...Ch. 7 - Prob. 42PCh. 7 - A bicycle rim has a diameter of 0.65 m and a...Ch. 7 - Prob. 44PCh. 7 - A small grinding wheel has a moment of inertia of...Ch. 7 - Prob. 46PCh. 7 - An objects moment of inertia is 2.0 kg m2. Its...Ch. 7 - Prob. 48PCh. 7 - A 200 g, 20-cm-diameter plastic disk is spun on an...Ch. 7 - Prob. 50PCh. 7 - A frictionless pulley, which can be modeled as a...Ch. 7 - Prob. 52PCh. 7 - If you lift the front wheel of a poorly maintained...Ch. 7 - Prob. 54PCh. 7 - A toy top with a spool of diameter 5.0 cm has a...Ch. 7 - Prob. 56PCh. 7 - A bicycle with 0.80-m-diameter tires is coasting...Ch. 7 - Prob. 58PCh. 7 - Prob. 59PCh. 7 - Prob. 60PCh. 7 - Prob. 61GPCh. 7 - The grap in Figure P7.56 shows the angular...Ch. 7 - A car with 58-cm-diameter tires accelerates...Ch. 7 - The cable lifting an elevator is wrapped around a...Ch. 7 - The 20-cm-diameter disk in Figure P7.59 can rotate...Ch. 7 - A combination lock has a 1.0-cm-diameter knob that...Ch. 7 - A 70 kg mans arm, including the hand, can be...Ch. 7 - Prob. 68GPCh. 7 - A reasonable estimate of the moment of inertia of...Ch. 7 - Prob. 70GPCh. 7 - The ropes in Figure P7.65 are each wrapped around...Ch. 7 - Flywheels are large, massive wheels used to store...Ch. 7 - A 1.0 kg ball and a 2.0 kg ball are connected by a...Ch. 7 - Prob. 76GPCh. 7 - A tradesman sharpens a knife by pushing it with a...Ch. 7 - MCAT-Style Passage Problems The Bunchberry The...Ch. 7 - The Bunchberry The bunchberry flower has the...Ch. 7 - The Bunchberry The bunchberry flower has the...Ch. 7 - Prob. 81MSPPCh. 7 - Prob. 82MSPPCh. 7 - Prob. 83MSPPCh. 7 - Prob. 84MSPP
Additional Science Textbook Solutions
Find more solutions based on key concepts
The method to classify two spheres whether it is solid or hollow if they have identical radius and masses.
Physics (5th Edition)
6. (Il) Two charged dust particles exert a force of 42 × 10-2 N on each other. What will be the force if they a...
Physics: Principles with Applications
A point charge q is at the center of a spherical shell of radius R carrying charge 2q spread uniformly over its...
Essential University Physics: Volume 2 (3rd Edition)
The pV-diagram of the Carnot cycle.
Sears And Zemansky's University Physics With Modern Physics
A point charge Q is placed a distance r0/2 above the surface of an imaginary spherical surface of radius r0 (Fi...
Physics for Scientists and Engineers with Modern Physics
3. What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in th...
The Cosmic Perspective (8th 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
- Consider the disk in Problem 71. The disks outer rim hasradius R = 4.20 m, and F1 = 10.5 N. Find the magnitude ofeach torque exerted around the center of the disk. FIGURE P12.71 Problems 71-75arrow_forwardA man is holding a 2.80-kg ball, as shown in the figure. The distance from the elbow joint to the ball is d= 32.5 cm, and the distance from the elbow joint to the insertion of the triceps muscle is d= 2.50cm. The mass of the lower arm, including the hand, is 3.60 kg, and its center of gravity is at a distance d= 13.6cm from the elbow joint. a)Draw a free body diagram of the forearm. b)What is the magnitude of the force FM, exerted by the triceps?arrow_forwardA man is holding a 2.80-kg ball, as shown in the figure. The distance from the elbow joint to the ball is d= 32.5 cm, and the distance from the elbow joint to the insertion of the triceps muscle is d= 2.50cm. The mass of the lower arm, including the hand, is 3.60 kg, and its center of gravity is at a distance d= 13.6cm from the elbow joint. a)Draw a free body diagram of the forearm. b)What is the magnitude of the force FM, exerted by the triceps? c)What is the force exerted by the humerus on the elbow joint?arrow_forward
- A 80-kg person raises his entire body weight on the ball of one foot as shown in the figure. Assuming that the center of gravity is 4.6 cm from the heel, calculate the force exerted by the Achilles tendon on the heel bone of his foot.arrow_forwardThe femur of a human leg (mass 10 kg, length 0.9 m) is in traction, as shown in the figure. The center of gravity of the leg is one-third of the distance from the pelvis to the bottom of the foot. Two objects, with masses m, and m2, m. m. are hung at the ends of the leg using pulleys to provide upward support. A third object of 8 kg is hung to provide tension along the leg. The body provides tension as well. Write a mathematical relationship relating m1 to m2 in terms of m, and numerical coefficients. 8 kg m1 = privacy policy terms of use contact us help about us careers tv W MacBook Airarrow_forwardTwo scales are separated by 2.00 m, and a plank of mass 4.00 kg is placed between them. Each scale is observed to read 2.00 kg. A person now lies on the plank, after which the right scale reads 30.0 kg and the left scale reads 50.0 kg. How far from the right scale is the person's center of gravity located?arrow_forward
- A circular plate with radius r = 0.941 m lies next to a rectangular plate with base br = 0.783 m and height hr = 0.898 m which lies next to a triangular, isosceles plate with base bt = 1.51 m and height ht = 0.80 m, see figure. Determine the common center of gravity of the three plates in the x-direction if the plates are the same thickness and are made of the same material.arrow_forwardStand with your heels and back against a wall and try to bend over and touch your toes. You’ll find that you have to stand away from the wall to do so without toppling over. Compare the minimum distance of your heels from the wall with that of a friend of the opposite sex. Who can touch their toes with their heels nearer to the wall males or females? On the average and in proportion to height, which sex has the lower center of gravity?arrow_forwardThe height of the center of gravity of a man is determined by letting him lie on a board that is balanced on two weighing scales, one on his head and one on his feet. Suppose that the height of this man is 1.9 m. As he has lied down on the board as shown, the scales on his head read 455 N and the scales on his feet weighted 401 N. Where is his center of gravity located with respect to his feet? Answer must be in meters and in two decimal places. Center of gravityarrow_forward
- A mountain biker tries to start pedalling in the mud. The total mass (80 kg, bike + biker) is distributed equally between the front and rear wheels. There is a loss of 10% of moment of force between pedal and the rear wheel. The diameter of wheels is 70 cm, and the static friction coefficient between tyre and the mud is 0.3. The pedal angle is 25° from the vertical and has a length of 20 cm. The force exerted by the cyclist is vertical. What is the maximal force that the biker can produce without skidding?Hint 1: ImageHint 2: the value of Mp, the moment around the pedals, is about 50 Nm.arrow_forwardA gravity board is a convenient and quick way to determine the location of the center of gravity of a person. It consists of a horizontal board supported by a fulcrum at one end and a scale at the other end. To demonstrate this in class, your physics professor calls on you to lie horizontally on the board with the top of your head directly above the fulcrum point as shown in the figure. The fulcrum is 2.00 m from the scale. In preparation for this experiment, you had accurately weighed yourself and determined your mass to be 65.0 kg. When you are at rest on the gravity board, the scale advances 300 N beyond its reading when the board is there by itself. Use this data to determine the location of your center of gravity relative to the top of your head. -2 m еВookarrow_forwardA 1.90-m-long barbell has a 21.0 kg weight on its left end and a 32.0 kg weight on its right end. If you ignore the weight of the bar itself, how far from the left end of the barbell is the center of gravity? Express your answer to three significant figures and include the appropriate units. Where is the center of gravity if the 9.00 kg mass of the barbell itself is taken into account? Express your answer to three significant figures and include the appropriate units.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.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 with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Static Equilibrium: concept; Author: Jennifer Cash;https://www.youtube.com/watch?v=0BIgFKVnlBU;License: Standard YouTube License, CC-BY