COLLEGE PHYSICS:VOL.1
2nd Edition
ISBN: 9780134862897
Author: ETKINA
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 8, Problem 1MCQ
A falling leaf usually flutters while falling. However, we have learned that the force that Earth exerts on an object is exerted at its center of mass and thus should not cause rotational motion. How can you resolve this contradiction?
A leaf is not a rigid body and the rule does not apply.
There are other forces exerted on the leaf as it falls besides the force exerted by Earth.
Some forces were not taken into account when we defined the center of mass.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Hi! I already asked this question, but I was provided with the wrong answer.
The picture below shows three small point masses.
A.) Find the x and y coordinates of the center of mass of this system.
B.) Find the moment of inertia of this system of masses about the y-axis. (In other words, the y-axis is the axis of rotation).
During a certain workout, you noticed that a 20-kg plate (say,
positioned 45 cm from the center) was on the left side of the
barbell while two 10-kg plates (say, one at 44.5 cm and the
other at 45.5 cm from the center) were on the right. Why is this
problematic?
O The center of gravity shifts to the left though still inside the barbell.
O The center of gravity shifts to the right though still inside the barbell.
The center of gravity shifts to the left, outside the barbell.
O The center of gravity shifts to the right, outside the barbell.
Chapter 8 Solutions
COLLEGE PHYSICS:VOL.1
Ch. 8 - Prob. 1RQCh. 8 - Review Question 8.2 Give an example of a situation...Ch. 8 - Review Question 8.3 You read the following...Ch. 8 - Prob. 4RQCh. 8 - Review Question 8.5 You are trying to hold a heavy...Ch. 8 - Review Question 8.6 Why is a ball hanging by a...Ch. 8 - A falling leaf usually flutters while falling....Ch. 8 - Prob. 2MCQCh. 8 - A hammock is tied with ropes between two trees. A...Ch. 8 - Prob. 4MCQ
Ch. 8 - 5. A physics textbook lies on top of a chemistry...Ch. 8 - What does it mean if the torque of a force is...Ch. 8 - Prob. 7MCQCh. 8 - 8. Why do you tilt your body forward when hiking...Ch. 8 - 9. What does it mean if the torque of a 10-N force...Ch. 8 - What is the maximum angle to the horizontal you...Ch. 8 - Prob. 11MCQCh. 8 - 12. Is it possible for an object not to be in...Ch. 8 - Explain the meaning of torque so that a friend not...Ch. 8 - Prob. 14CQCh. 8 - What are the two conditions of equilibrium? What...Ch. 8 - Give three examples of situations in which an...Ch. 8 - The force that the body muscles exert on bones...Ch. 8 - A ladder leans against a wall. Construct a force...Ch. 8 - Using a crowbar, a person can remove a nail by...Ch. 8 - 20. Is it more difficult to do a sit-up with your...Ch. 8 - Sit on a chair with your feet straight down at the...Ch. 8 - Can you balance the tip of a wooden ruler...Ch. 8 - Try to balance a sharp wooden pencil on your...Ch. 8 - 24. Design a device that you can use to...Ch. 8 - Explain why it is easier to keep your balance...Ch. 8 - A carpenters trick to keep nails from bending when...Ch. 8 - Determine the torques about the axis of rotation P...Ch. 8 - 2. Three 200-N forces are exerted on the beam...Ch. 8 - 3. * A 2.0-m-long, 15-kg ladder is resting against...Ch. 8 - Figure P8.4 shows two different situations where...Ch. 8 - Three friends tie three ropes in a knot and pull...Ch. 8 - Prob. 6PCh. 8 - * Kate joins Jim, Luis, and Adrienne in the...Ch. 8 - You hang a light in front of your house using an...Ch. 8 - * Find the values of the forces the ropes exert on...Ch. 8 - Prob. 10PCh. 8 - Determine the masses m1 and m2 of the two objects...Ch. 8 - * Lifting an engine You work in a machine shop and...Ch. 8 - 13. * More lifting You exert a 630-N force on rope...Ch. 8 - Prob. 14PCh. 8 - 15. * Tightrope walking A tightrope walker wonders...Ch. 8 - 16. * Lifting patients An apparatus to lift...Ch. 8 - 17. A father (80 kg), mother (56 kg), daughter (16...Ch. 8 - Prob. 18PCh. 8 - * You place a 3.0-m-long board symmetrically...Ch. 8 - Prob. 20PCh. 8 - Prob. 21PCh. 8 - Prob. 22PCh. 8 - 23. EST Compare the two different designs of...Ch. 8 - Ray decides to paint the outside of his uncles...Ch. 8 - 25. * A 2.0-m-long uniform beam of mass 8.0 kg...Ch. 8 - * A uniform beam of length / and mass m supports a...Ch. 8 - Prob. 27PCh. 8 - Prob. 28PCh. 8 - Prob. 29PCh. 8 - Prob. 30PCh. 8 - 31. * An 80-kg clown sits on a 20-kg bike on a...Ch. 8 - s center of mass? (Hint: You can think of cutting...Ch. 8 - Leg support A persons broken leg is kept in place...Ch. 8 - Prob. 34PCh. 8 - Prob. 35PCh. 8 - * If the force F shown in Figure P8.35 is 840 N...Ch. 8 - Prob. 37PCh. 8 - 38. * You decide to hang another plant from a...Ch. 8 - Prob. 39PCh. 8 - * What mechanical work must you do to lift a log...Ch. 8 - 41. * A 70-g meter stick has a 30-g piece of...Ch. 8 - * You are trying to tilt a very tall refrigerator...Ch. 8 - Prob. 43PCh. 8 - 44. * You have an Atwood machine (see Figure 4.9 )...Ch. 8 - * EST You stand sideways in a moving train....Ch. 8 - 46. EST Your hand holds a liter of milk (mass...Ch. 8 - EST Body torque You hold a 4.0-kg computer....Ch. 8 - Prob. 48GPCh. 8 - 49. BIO Using triceps to push a table A man pushes...Ch. 8 - Prob. 50GPCh. 8 - Prob. 51GPCh. 8 - Prob. 52GPCh. 8 - 53.* BIO Dumbbell lift IA woman lifts a 3.6-kg...Ch. 8 - s shoulder joint exerts on her humerus.Ch. 8 - Prob. 55GPCh. 8 - * Eiichi has purchased an adjustable hand grip to...Ch. 8 - 57. *BIO While browsing books on neurophysiology,...Ch. 8 - 58. ** Touch detector You have two force sensors...Ch. 8 - * An 80-kg person stands at one end of a 130-kg...Ch. 8 - 61. EST Two people (50 kg and 75 kg) holding hands...Ch. 8 - Prob. 62GPCh. 8 - BIO Muscles work in pairs Skeletal muscles produce...Ch. 8 - BIO Muscles work in pairs Skeletal muscles produce...Ch. 8 - BIO Muscles work in pairs Skeletal muscles produce...Ch. 8 - BIO Muscles work in pairs Skeletal muscles produce...Ch. 8 - BIO Improper lifting and the back A careful study...Ch. 8 - BIO Improper lifting and the back A careful study...Ch. 8 - BIO Improper lifting and the back A careful study...Ch. 8 - BIO Improper lifting and the back A careful study...
Additional Science Textbook Solutions
Find more solutions based on key concepts
Lunar astronauts placed a reflector on the Moon’s surface, off which a laser beam is periodically reflected. Th...
University Physics Volume 2
3. The lateral surface area of a solid is
always equal to total surface area.
never equal to total surface area...
Applied Physics (11th Edition)
27. An old-fashioned single-play vinyl record rotates on a turntable at 45 rpm. What are (a) the angular veloci...
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
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)
The bottom of a swimming pool looks to be 1.5 m below the surface. Find the pools actual depth.
Essential University Physics (3rd Edition)
Which of the following is not a source of energy for at least some forms of life on Earth? (a) inorganic chemic...
Life in the Universe (4th 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 particle of mass m moves along a straight line with constant velocity v0 in the x direction, a distance b from the x axis (Fig. P13.10). (a) Does the particle possess any angular momentum about the origin? (b) Explain why the amount of its angular momentum should change or should stay constant. (c) Show that Keplers second law is satisfied by showing that the two shaded triangles in the figure have the same area when . Figure P13.10arrow_forwardThe three masses shown in Figure 1) are connected by massless, rigid rods. Figure B A y P 200 g 10 cm 10 cm 100 g C 8 cm 1 of 1 What is the z-coordinate of the center of mass? Express your answer with the appropriate units. View Available Hint(s) Icm= Value Submit Part B h 4 What is the y-coordinate of the center of mass? Express your answer with the appropriate units View Available Hint(s) 1 Units A ?arrow_forwardВ 400 kg 6 m 8 m A 100 kg 50 kg 1a. Calculate the coordinates for the center of mass for the above object. Note that a coordinate system has been provided for you. Make an “x" at the approximate location of the center of mass in the above figure. 1b. Calculate the moment of inertia of this object about an axis that passes through the center of mass and is perpendicular to the paper.arrow_forward
- A hollow spherical shell with mass 1.75 kgkg rolls without slipping down a slope that makes an angle of 40.0 degrees with the horizontal. a.) Find the magnitude of the acceleration acmacma_cm of the center of mass of the spherical shell. Take the free-fall acceleration to be ggg = 9.80 m/s2m/s2 . =3.78 b) Find the magnitude of the frictional force acting on the spherical shell. Take the free-fall acceleration to be ggg = 9.80 m/s2m/s2 . =4.41 c)Find the minimum coefficient of friction μμmu needed to prevent the spherical shell from slipping as it rolls down the slope. i need help with C) ive got the first two.arrow_forwardPlease Asaparrow_forwardForces which are identical in terms of magnitude are are applied to three different locations on a regular hexagon that is initially at rest and not rotating. How will the hexagon rotate and in what direction will the hexagon's center of mass accelerate as a result of the action of these three forces? Select TWO answers.arrow_forward
- A uniform rod is set up so that it can rotate about an axis at perpendicular to one of its ends. The length and mass of the rod are 0.877 m0.877 m and 1.23 kg1.23 kg , respectively. A force of constant magnitude ?F acts on the rod at the end opposite the rotation axis. The direction of the force is perpendicular to both the rod's length and the rotation axis. Calculate the value of ?F that will accelerate the rod from rest to an angular speed of 6.61 rad/s6.61 rad/s in 8.07 s8.07 s .arrow_forwardConsider the woman doing push-ups in the figure. She has a mass of 49.2 kg, and the distance from her feet to her center of mass is 0.96 m, while the distance from her feet to her hands is 1.75m. a. What force in newtons should the woman in the figure 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 1.95 cm, and she exerts force on the floor at a horizontal distance of 15.5 cm from the elbow joint. Calculate the magnitude of the force in newtons for each triceps muscle. c. How much work in joules does she do if her center of mass rises 0.27 m? d. What is her useful power output, in watts, if she does 25 pushups in one minute? For the sake of simplicity, ignore any power used by her muscles lowering her body during each pushup.arrow_forwardA 40-kg boy is standing on the edge of a stationary 30-kg platform that is free to rotate. The boy tries to walk around the platform in a counterclockwise direction. As he does: O both go around with equal angular velocities but in opposite directions. O the platform rotates in a clockwise direction while the boy goes around in a counterclockwise direction relative to the ground. O the platform rotates in a clockwise direction just fast enough so that the boy remains stationary relative to the ground. O the platform doesn't rotate.arrow_forward
- The center of mass of a person may be determined by an arrangement such as the one shown in the figure below. A light plank rests on two scales separated by a distance of d = 1.80 m and reading Fg1 = 470 N and Fg2 = 260 N. Determine the distance of the girl's center of mass from her feet.arrow_forwardA person is pushing a fully loaded 20.65 kg wheelbarrow at constant velocity along a plank that makes an angle ?=45.0∘with the horizontal. The load is distributed such that the center of mass of the wheelbarrow is exactly halfway along its length ?. What is the magnitude of the total force ?? the person must apply so that the wheelbarrow is parallel to that plank? You may neglect the radius of the wheel in your analysis. The gravitational acceleration is ?=9.81 m/s2.arrow_forwardIn a judo foot-sweep move, you sweep your opponent's left foot out from under him while pulling on his gi (uniform) toward that side. As a result, your opponent rotates around his right foot and onto the mat. The figure shows a simplified diagram of your opponent as you face him, with his left foot swept out. The rotational axis is through point O. The gravitational force Fg on him effectively acts at his center of mass, which is a horizontal distance d = 21 cm from point O. His mass is 73 kg, and his rotational inertia about point O is 65 kg.m². What is the magnitude of his initial angular acceleration about point O if your pull Fa on his gi is (a) negligible and (b) horizontal with a magnitude of 300 N and applied at height h = 1.4 m? Assume free-fall acceleration to be equal to 9.81 m/s². (a) Number i Units (b) Number Units com F >arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityPhysics 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
University Physics Volume 1
Physics
ISBN:9781938168277
Author:William Moebs, Samuel J. Ling, Jeff Sanny
Publisher:OpenStax - Rice University
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
Moment of Inertia; Author: Physics with Professor Matt Anderson;https://www.youtube.com/watch?v=ZrGhUTeIlWs;License: Standard Youtube License