Physics (5th Edition)
5th Edition
ISBN: 9780321976444
Author: James S. Walker
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 11, Problem 51PCE
Predict/Explain A student rotates on a frictionless piano stool with his arms outstretched a heavy weight in each hand Suddenly he lets go of the weights, and they fall to the floor As a result does the student’s angular speed increase, decrease or stay the same? (b) Choose the best explanation from among the following:
- I. The loss of
angular momentum when the weights are dropped causes the student to rotate more slowly. - II. The student s moment of inertia is decreased by dropping the weights
- III. Dropping the weights exerts no torque on the student, but the floor exerts a torque on the weights when they land.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionChapter 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
24.25 An air capacitor is made from two flat parallel plates 1.50 mm apart. The magnitude of charge on each pla...
University Physics with Modern Physics (14th Edition)
In 2008, Australian Emma Snowsill set an unofficial record in the womens Olympic triathlon, completing the 1.5-...
Essential University Physics (3rd Edition)
how a room which absorbs all sound waves, can be used to study how bats find their food.
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
8. A 1000 kg car pushes a 2000 kg truck that has a dead battery. When the driver steps on the accelerator, the ...
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (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
- Two ponies of equal mass are initially at diametrically opposite points on the rim of a large horizontal turntable that is turning freely on a frictionless. vertical axle through its center. The ponies simultaneously start walking toward each other across the turntable, (i) As they walk, what happens to the angular speed of the turntable? (a) It increases, (b) h decreases, (c) It stays constant. (Consider the ponies-turntable system in this process and answer yes or no for the following questions. (ii) Is the mechanical energy of the system conserved? (iii) Is the momentum of the system conserved? (iv) Is the angular momentum of the system conserved?arrow_forwardTwo astronauts (Fig. P8.80), each haring a mass of 75.0 kg, are connected by a 10.0-m rope of negligible mass. They are isolated in space, moving in circles around the point halfway between them at a speed of 5.00 m/s. Treating the astronauts as particles, calculate (a) the magnitude of the angular momentum and (b) the rotational energy of the system. By pulling on the rope, the astronauts shorten the distance between them to 5.00 m. (c) What is the new angular momentum of the system? (d) What are their new speeds? (e) What is the new rotational energy of the system? (f) How much work is done by the astronauts in shortening the rope? Figure P8.80 Problems 80 and 81arrow_forwardUnreasonable Results An advertisement claims that an 800-kg car is aided by its 20.0-kg flywheel, which can accelerate the car from rest to a speed of 30.0 m/s. The flywheel is a disk with a 0.150-m radius. (a) Calculate the angular velocity the flywheel must have if 95.0% of its rotational energy is used to get the car up to speed. (b) What is unreasonable about the result? (c) Which premise is unreasonable or which premises are inconsistent?arrow_forward
- While punting a football, a kicker rotates his leg about the hip joint. The moment of inertia of the leg is 3.75kg-m2 and its rotational kinetic energy is 175 J. (a) What is the angular velocity of the leg? (b) What is the velocity of tip of the punter's shoe if it is 1.05 m from the hip joint? (c) Explain how the football can be given a velocity greater than the tip of the shoe (necessary for a decent kick distance).arrow_forwardA carnival carousel accelerates nonuniformly from rest, moving through an angle of 8.60 rad in 6.00 s. If its turning at 3.30 rad/s at that time, find (a) its average angular speed, and (b) average angular acceleration during that time interval. (See Section 7.1.)arrow_forwardOne method of pitching a softball is called the wind-mill delivery method, in which the pitchers arm rotates through approximately 360 in a vertical plane before the 198-gram ball is released at the lowest point of the circular motion. An experienced pitcher can throw a ball with a speed of 98.0 mi/h. Assume the angular acceleration is uniform throughout the pitching motion and take the distance between the softball and the shoulder joint to be 74.2 cm. (a) Determine the angular speed of the arm in rev/s at the instant of release, (b) Find the value of the angular acceleration in rev/s2 and the radial and tangential acceleration of the ball just before it is released, (c) Determine the force exerted on the ball by the pitchers hand (both radial and tangential components) just before it is released.arrow_forward
- Competitive divers pull their limbs in and curl up their bodies when they do flips. Just before entering the water, they fully extend their limbs to enter straight down. Explain the effect of both actions on their angular velocities. Also explain the effect on their angular momenta.arrow_forwardWhile punting a football, a kicker rotates his leg about the hip joint. The moment of inertia of the leg is 3.75kgm2 and its rotational kinetic energy is 175 J. (a) What is the angular velocity of the leg? (b) What is the velocity of tip of the punter’s shoe if it is 1.05 m from the hip joint?arrow_forwardUnreasonable Results A gymnast doing a forward flip lands on the mat and exerts a 500- Nm torque to slow and then reverse her angular velocity. Her initial angular velocity is 10.0 rad/s, and her moment of inertia is 0.050kgm2. (a) What time is required for her to exactly reverse her spin? (b) What is unreasonable about the result? (c) Which premises are unreasonable or inconsistent?arrow_forward
- Integrated Concepts When kicking a football, the kicker rotates his leg about the hip joint. (a) If the velocity of the tip of the kicker's shoe is 35.0 m/s and the hip joint is 1.05 m from the tip of the shoe, what is the shoe tip's angular velocity? (b) The shoe is in contact with the initially stationary 0.500 kg football for 20.0 ms. What average force is exerted on the football to give it a velocity of 20.0 m/s? (c) Find the maximum range of the football, neglecting air resistance.arrow_forwardA 60.0-kg woman stands at the rim of a horizontal turntable having a moment of inertia of 500 kg m2 and a radius of 2.00 m. The turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center. The woman then starts walking around the rim clock-wise (as viewed from above the system) at a constant speed of 1.50 m/s relative to Earth. (a) In what direction and with what angular speed does the turntable rotate? (b) How much work does the woman do to set herself and the turntable into motion?arrow_forwardCalculate the moment of inertia of a skater given the following information. (a) The 60.0-kg skater is approximated as a cylinder that has a 0.110-m radius. (b) The skater with arms extended is approximately a cylinder that is 52.5 kg, has a 0.110-m radius, and has two 0.900-m-long arms which are 3.75 kg each and extend straight out from the cylinder like rods rotated about their ends.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 UniversityCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author: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
College Physics
Physics
ISBN:9781285737027
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
What is Torque? | Physics | Extraclass.com; Author: Extraclass Official;https://www.youtube.com/watch?v=zXxrAJld9mo;License: Standard YouTube License, CC-BY