College Physics: A Strategic Approach (3rd Edition)
3rd Edition
ISBN: 9780321879721
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 7, Problem 61GP
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 solutionStudents 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?
A 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?
Chapter 7 Solutions
College Physics: A Strategic Approach (3rd 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 - If you are using a wrench to loosen a very...Ch. 7 - A screwdriver with a very thick handle requires...Ch. 7 - If you have ever driven a truck, you likely found...Ch. 7 - A common type of door stop is a wedge made of...Ch. 7 - A student gives a steady push to a ball at the end...Ch. 7 - Prob. 10CQ
Ch. 7 - Prob. 11CQCh. 7 - If you grasp a hammer by its lightweight handle...Ch. 7 - Suppose you have two identical-looking metal...Ch. 7 - The moment of inertia of a uniform rod about an...Ch. 7 - The wheel in Figure Q7.15 is rolling to the right...Ch. 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 - Suppose a bolt on your car engine needs to be...Ch. 7 - Prob. 19MCQCh. 7 - A typical compact disk has a mass of 15 g and a...Ch. 7 - Suppose manufacturers increase the size of compact...Ch. 7 - Two horizontal rods are each held up by vertical...Ch. 7 - Prob. 23MCQCh. 7 - A particle undergoing circular motion in the...Ch. 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 - A Ferris wheel rotates at an angular velocity of...Ch. 7 - A turntable rotates counterclockwise at 78 rpm. A...Ch. 7 - A fast-moving superhero in a comic book runs...Ch. 7 - Figure P7.9 shows the angular position of a...Ch. 7 - The angular velocity (in rpm) of the blade of a...Ch. 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 - A computer hard disk starts from rest, then speeds...Ch. 7 - The crankshaft in a race car goes from rest to...Ch. 7 - Reconsider the situation in Example 7.10. If Luis...Ch. 7 - Balls are attached to light rods and can move in...Ch. 7 - Six forces, each of magnitude either F or 2F, are...Ch. 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 - A professors office door is 0.91 m wide, 2.0 m...Ch. 7 - In Figure P7.22, force F2, acts half as far from...Ch. 7 - Tom and Jerry both push on the 3.00-m-diameter...Ch. 7 - What is the net torque on the bar shown in Figure...Ch. 7 - What is the net torque on the bar shown in Figure...Ch. 7 - What is the net torque on the bar shown in Figure...Ch. 7 - Prob. 27PCh. 7 - Prob. 28PCh. 7 - Hold your arm outstretched so that it is...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 - Two thin beams are joined end-to-end as shown in...Ch. 7 - Figure P7.36 shows two thin beams joined at right...Ch. 7 - A regulation table tennis ball is a thin spherical...Ch. 7 - Three pairs of balls are connected by very light...Ch. 7 - A playground toy has four seats, each 5.0 kg,...Ch. 7 - A solid cylinder with a radius of 4.0 cm has the...Ch. 7 - A bicycle rim has a diameter of 0.65 m and a...Ch. 7 - a. What is the moment of inertia of the door in...Ch. 7 - A small grinding wheel has a moment of inertia of...Ch. 7 - While sitting in a swivel chair, you push against...Ch. 7 - An objects moment of inertia is 2.0 kg m2. Its...Ch. 7 - A 200 g, 20-cm-diameter plastic disk is spun on an...Ch. 7 - The 2.5 kg object shown in Figure P7.47 has a...Ch. 7 - A frictionless pulley, which can be modeled as a...Ch. 7 - If you lift the front wheel of a poorly maintained...Ch. 7 - On page 207 there is a photograph of a girl...Ch. 7 - A toy top with a spool of diameter 5.0 cm has a...Ch. 7 - A bicycle with 0.80-m-diameter tires is coasting...Ch. 7 - Figure P7.55 shows the angular...Ch. 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 - The three masses shown in Figure P7.62 are...Ch. 7 - A reasonable estimate of the moment of inertia of...Ch. 7 - Starting from rest, a 12-cm-diameter compact disk...Ch. 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 - A 1.5 kg block is connected by a rope across a...Ch. 7 - The two blocks in Figure P7.69 are connected by a...Ch. 7 - The 2.0 kg, 30-cm-diameter disk in Figure P7.70 is...Ch. 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 - The Bunchberry The bunchberry flower has the...Ch. 7 - Prob. 76MSPPCh. 7 - Prob. 77MSPPCh. 7 - Prob. 78MSPP
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
- Find the net torque on the wheel in Figure P10.23 about the axle through O, taking a = 10.0 cm and b = 25.0 cm. Figure P10.23arrow_forwardConsider 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_forward
- 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 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_forwardA 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_forwardA 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_forward
- A 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_forwardIn the figure, a lead brick rests horizontally on cylinders A and B. The areas of the top faces of the cylinders are related by AA= 2.8 AB; the Young's moduli of the cylinders are related by Ea= 2.3 Eg. The cylinders had identical lengths before the brick was placed on them. What fraction of the brick's mass is supported (a) by cylinder A and (b) by cylinder B? The horizontal distances between the center of mass of the brick and the centerlines of the cylinders are dafor cylinder A and dg for cylinder B. (c) What is the ratio da/dg? da ! dg com of brick A B (a) Number i Units (b) Number i Units (c) Number i Unitsarrow_forward
- In the figure, a lead brick rests horizontally on cylinders A and B. The areas of the top faces of the cylinders are related by Aa= 2.4 Ag: the Young's moduli of the cylinders are related by EA 1.6 Ea. The cylinders had identical lengths before the brick was placed on them. What fraction of the brick's mass is supported (a) by cylinder A and (b) by cylinder B? The horizontal distances between the center of mass of the brick and the centerlines of the cylinders are d,for cylinder A and dg for cylinder B. (c) What is the ratio d,/dg? com of brickarrow_forwardThe figure (a) shows an outstretched arm with a mass of 4.2kg. The arm is 56 cm long, and its center of gravity is 21 cm from the shoulder. The hand at the end of the arm holds a 6.0-kg mass. (Figure 1) 56 cm 21 en 6.0 kg (a) Deltoid muscle 5.0 15 18 cm (b) What is the torque about the shoulder due to the weights of the arm and the 6.0-kg mass? If the arm is held in equilibrium by the deltoid muscle, whose force on the arm acts 5.0 degrees below the horizontal at a point 18 cm from the shoulder joint (the figure (b)), what is the force exerted by the muscle?arrow_forwardA 4.80-m-long, 500 kgkg steel uniform beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 70 kgkg construction worker stands at the far end of the beam. What is the magnitude of the torque about the bolt due to the worker and the weight of the beam? Express your answer in newton-meters.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 LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author: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
Physics
ISBN:9781337553278
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: 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