College Physics
2nd Edition
ISBN: 9780134601823
Author: ETKINA, Eugenia, Planinšič, G. (gorazd), Van Heuvelen, Alan
Publisher: Pearson,
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Chapter 9, Problem 3MCQ
In terms of the torque needed to rotate your leg as you run, would it be better to have a long calf and short thigh, or vice versa?
a. Long calf and short thigh
b. Short calf and long thigh
c. Does not matter
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Chapter 9 Solutions
College Physics
Ch. 9 - Review Question 9.1 Visualize an ice skater...Ch. 9 - Review Question 9.2 A solid wooden ball and a...Ch. 9 - Review Question 9.3 How is Newton’s second law for...Ch. 9 - Review Question 9.4 After a playground...Ch. 9 - Review Question 9.5 Will a can of watery chicken...Ch. 9 - Review Question 9.6 How can you explain the...Ch. 9 - Is it easier to open a door that is made of a...Ch. 9 - 2. You push a child on a swing. Why doesn’t the...Ch. 9 - In terms of the torque needed to rotate your leg...Ch. 9 - Suppose that two bicycles have equal overall mass,...
Ch. 9 - When riding a 10-speed bicycle up a hill, a...Ch. 9 - 6 The objects in Figure Q9.6 are made or two...Ch. 9 - 7. Select all the pairs below in which the two...Ch. 9 - If you turn on a coffee grinding machine sitting...Ch. 9 - A bowling ball is rolling without skidding down an...Ch. 9 - 10. The Mississippi River carries sediment from...Ch. 9 - Two disks are cut from the same uniform board. The...Ch. 9 - A spinning raw egg, if stopped momentarily and men...Ch. 9 - Compare the magnitude of Earth's rotational...Ch. 9 - You lay a pencil on a smooth desk (ignore sliding...Ch. 9 - If you watch the dive of an Olympic diver, you...Ch. 9 - 17. Explain why you do not tip over when riding a...Ch. 9 - Prob. 18CQCh. 9 - 19. Why do tightrope walkers carry long, heavy...Ch. 9 - The sweeping second hand on your wall clock is 20...Ch. 9 - 2. You find an old record player in your attic....Ch. 9 - 3. * Consider again the turntable described in the...Ch. 9 - 4. You step on the gas pedal in your car, and the...Ch. 9 - You pull your car into your driveway and stop. The...Ch. 9 - 6. An old wheat-grinding wheel in a museum...Ch. 9 - Centrifuge A centrifuge at the same museum is used...Ch. 9 - Potters wheel A fly sits on a potters wheel 0.30 m...Ch. 9 - 9. * During your tennis serve, your racket and arm...Ch. 9 - 10. * An ant clings to the outside edge of the...Ch. 9 - 11. * The speedometer on a bicycle indicates that...Ch. 9 - * You pedal your bicycle so that its wheel's...Ch. 9 - Mileage gauge The odometer on an automobile...Ch. 9 - *Speedomter The speedometer on an automobile...Ch. 9 - 15 * Ferns wheel A Ferris wheel starts at rest,...Ch. 9 - 16. * You push a disk-shaped platform tangentially...Ch. 9 - s rotational acceleration would be in ran/s2 if...Ch. 9 - 18. A 0.30-kg ball is attached at the end or a...Ch. 9 - 19. Centrifuge A centrifuge with a rotational...Ch. 9 - Airplane turbine what is the average torque needed...Ch. 9 - * A turntable turn ng at rotational speed 33 rpm...Ch. 9 - 22. * The solid pulley in Figure P9.22 consists...Ch. 9 - * The pulley shown in Figure P9.22 is initially...Ch. 9 - The pulley shown in Figure P9.22 is initially...Ch. 9 - 28. Derive an expression Tor the rotational...Ch. 9 - * Repeat the previous problem for an axis...Ch. 9 - Repeat the previous problem for axis BC, which...Ch. 9 - 31. * Merry-go-round A mechanic needs to replace...Ch. 9 - 32. * A small 0.80-kg train propelled by a fan...Ch. 9 - * Motor You wish to buy a motor that will be used...Ch. 9 - 34. ** A string wraps around a 6.0-kg wheel of...Ch. 9 - * Elena, a black belt in tae kwon do, is...Ch. 9 - Prob. 36PCh. 9 - 37. * Fire escape A unique fire escape for a...Ch. 9 - 38. ** An Atwood machine is shown in Example 9.4 ....Ch. 9 - onTruckandF2onbucket that the rope exerts on the...Ch. 9 - * A thin rod of length L and mass m rotates around...Ch. 9 - 41. * (a) Determine the rotaticnal momentum o’ a...Ch. 9 - Ballet A ballet student with her arms and a leg...Ch. 9 - * A 0.20-kg block moves at the end of a 0.50-m...Ch. 9 - * Puck on a string You attach a 100-g puck to a...Ch. 9 - 0. The student then turns the bicycle wheel over...Ch. 9 - 47. Neutron star An extremely dense neutron star...Ch. 9 - 48. * A boy of mass m is standing on the edge of a...Ch. 9 - 50. A grinding wheel with rotational inertia I...Ch. 9 - * The rotational speed of a flywheel increases by...Ch. 9 - B,/KrotA.Ch. 9 - * Flywheel energy for car The U.S. Department of...Ch. 9 - * Flywheel energy Engineers at the University of...Ch. 9 - 56. ** Rotating student A student sitting on a...Ch. 9 - * A turntable whose rotational inertia is...Ch. 9 - 58. **Repeat the previous problem, only assume...Ch. 9 - * Merry-go-round A carnival merry-go-round has a...Ch. 9 - *Est You hold an apple by its stem between your...Ch. 9 - * Stopping Earths rotation Suppose that Superman...Ch. 9 - BIO EST Punting a football Estimate the tangential...Ch. 9 - * BIO Triceps and darts Your upper arm is...Ch. 9 - 66. * BIO Bowling At the start of your throw of a...Ch. 9 - 67. ** Bio Leg lift You are doing one-leg leg...Ch. 9 - * A horizontal, circular platform can rotate...Ch. 9 - 69. * You have an empty cylindrical metal can and...Ch. 9 - ** in the previous problem, each nut has a mass of...Ch. 9 - 71. * Superball If you give a superball backspin...Ch. 9 - Prob. 72GPCh. 9 - 73. * EST White dwarf A star the size of our Sun...Ch. 9 - Tidal energy Tides are now used so gene-ate...Ch. 9 - Tidal energy Tides are now used so gene-ate...Ch. 9 - Tidal energy Tides are now used so gene-ate...Ch. 9 - Tidal energy Tides are now used so gene-ate...Ch. 9 - Tidal energy Tides are now used so gene-ate...Ch. 9 - Tidal energy Tides are now used so gene-ate...
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