Conceptual Physics / MasteringPhysics (Book & Access Card)
12th Edition
ISBN: 9780321908605
Author: Paul G. Hewitt
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 7, Problem 93RCQ
Scissors for cutting paper have long blades and short handles, whereas metal-cutting shears have long handles and short blades. Bolt cutters have very long handles and very short blades. Why is this so?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Certain types of dinosaurs were bipedal (walked on two legs). What is a good reason that these creatures invariably had long tails if they had long necks?
Your answer is partially correct.
African elephants are the largest land animals. They consume approximately 10% of their body weight in food each day, which for an
adult male, can be 1000 lb. of vegetation! Their diet consists mostly of grasses, bamboo, tree bark, and fruit. They also like to dine on
tree leaves. To reach them, they often stand up on their hind legs and extend their trunks (see the figure). The elephant in the figure is
in equilibrium. The location of the elephant's center of mass is shown, and the axis of rotation has been chosen to correspond to the hip
joint. The forces in the elephant's free-body diagram are shown, and there is a static friction force between the elephant's back feet
and the ground. Use the following information and calculate the magnitude of the tension in the elephant's trunk T (m = 4540 kg, FN
= 'fs=133 cm, rcg = 76.0 cm, r = 229 cm).
Number
1103.035
+x
Axis of
rotation
Units
N
165⁰
60⁰
W
=FN
30°
FN
10°
Michael Poliza/Caters News Agency
When throwing a football you are always instructed to follow-through. What is the advantage of this? You are also instructed to stand with your feet about shoulder-width apart. What is the advantage of this?
Chapter 7 Solutions
Conceptual Physics / MasteringPhysics (Book & Access Card)
Ch. 7 - When is energy most evident?Ch. 7 - A force sets an object in motion. When the force...Ch. 7 - Cite an example in which a force is exerted on an...Ch. 7 - Prob. 4RCQCh. 7 - Exactly what is it that enables an object to do...Ch. 7 - If both sacks in the preceding question are lifted...Ch. 7 - A car is raised a certain distance in a...Ch. 7 - Two cars are raised to the same elevation on...Ch. 7 - When is the potential energy of something...Ch. 7 - Prob. 10RCQ
Ch. 7 - 11. Compared with a car moving at some original...Ch. 7 - If you push a crate horizontally with 100 N across...Ch. 7 - 13. How does speed affect the friction between a...Ch. 7 - 14. What will be the kinetic energy of a pile...Ch. 7 - An apple hanging from a limb has potential energy...Ch. 7 - 16. What is the source of energy in sunshine?
Ch. 7 - Prob. 17RCQCh. 7 - 18. Can a machine multiply input force? Input...Ch. 7 - 19. If a machine multiplies force by a factor of...Ch. 7 - 20. A force of 50 N is applied to the end of a...Ch. 7 - 21. What is the efficiency of a machine that...Ch. 7 - Prob. 22RCQCh. 7 - Prob. 23RCQCh. 7 - Prob. 24RCQCh. 7 - 25. Can we correctly say that hydrogen is a new...Ch. 7 - Prob. 26RCQCh. 7 - Prob. 27RCQCh. 7 - Prob. 28RCQCh. 7 - Prob. 29RCQCh. 7 - Prob. 30RCQCh. 7 - Prob. 31RCQCh. 7 - Power = work/time: P = W / t 32. Show that 50 W of...Ch. 7 -
33. Show that about 786 W of power is expended...Ch. 7 - Prob. 34RCQCh. 7 - 35. Show that the gravitational potential energy...Ch. 7 - Kinetic energy= 1 2 mass X speed : KE= 1 2 m v 2...Ch. 7 - 37. Calculate the kinetic energy of an 84-kg...Ch. 7 - Work-energy theorem: Work = KE
38. Show...Ch. 7 - 39. Show that a 2,500,000-J change in kinetic...Ch. 7 - Prob. 40RCQCh. 7 - Prob. 41RCQCh. 7 - 42. (a) How much work is done when you push a...Ch. 7 - 43. This question is typical on some driver’s...Ch. 7 - Belly-flop Bernie dives from atop a tall flagpole...Ch. 7 - Nellie Newton applies a force of 50 N to the end...Ch. 7 - 46. Consider an ideal pulley system. If you pull...Ch. 7 - 47. In raising a 5000-N piano with a pulley...Ch. 7 - 48. In the hydraulic machine shown, you observe...Ch. 7 - 49. How many watts of power do you expend when you...Ch. 7 - Emily holds a banana of mass m over the edge of a...Ch. 7 - 51. The mass and speed of the three vehicles, A,...Ch. 7 - 52. A ball is released from rest at the left of...Ch. 7 - 53. The roller coaster ride starts from rest at...Ch. 7 - Prob. 54RCQCh. 7 - Prob. 55RCQCh. 7 - Why do you do no work on a 25-kg backpack when you...Ch. 7 - If your friend pushes a lawnmower four times as...Ch. 7 - Why does one get tired pushing against a...Ch. 7 - Prob. 59RCQCh. 7 - Prob. 60RCQCh. 7 - Prob. 61RCQCh. 7 - When a rifle with a longer barrel is fired, the...Ch. 7 - Prob. 63RCQCh. 7 - 64. You and a flight attendant toss a ball back...Ch. 7 - Prob. 65RCQCh. 7 - Prob. 66RCQCh. 7 - Prob. 67RCQCh. 7 - Prob. 68RCQCh. 7 - 69. A physics instructor demonstrates energy...Ch. 7 - Prob. 70RCQCh. 7 - Prob. 71RCQCh. 7 - 72. A moving hammer hits a nail and drives it into...Ch. 7 - Prob. 73RCQCh. 7 - 74. Why does the force of gravity do work on a car...Ch. 7 - Prob. 75RCQCh. 7 - Prob. 76RCQCh. 7 - Prob. 77RCQCh. 7 - Prob. 78RCQCh. 7 - Prob. 79RCQCh. 7 - Prob. 80RCQCh. 7 - Prob. 81RCQCh. 7 - Prob. 82RCQCh. 7 - Prob. 83RCQCh. 7 - Prob. 84RCQCh. 7 - Prob. 85RCQCh. 7 - When the velocity of an object is doubled, by what...Ch. 7 - Prob. 87RCQCh. 7 - Prob. 88RCQCh. 7 - Prob. 89RCQCh. 7 - If your momentum is zero, is your kinetic energy...Ch. 7 - 91. If two objects have equal kinetic energies, do...Ch. 7 - 92. Two lumps of clay with equal and opposite...Ch. 7 - Scissors for cutting paper have long blades and...Ch. 7 - Prob. 94RCQCh. 7 - Prob. 95RCQCh. 7 - Prob. 96RCQCh. 7 - Prob. 97RCQCh. 7 - Prob. 98RCQCh. 7 - Prob. 99RCQCh. 7 - 100. Consider the identical balls released from...Ch. 7 - Prob. 101RCQCh. 7 - Prob. 102RCQCh. 7 - Prob. 103RCQCh. 7 - Prob. 104RCQCh. 7 - Prob. 105RCQCh. 7 - Prob. 106RCQCh. 7 - Prob. 107RCQCh. 7 - Prob. 108RCQCh. 7 - 109. Your discussion partner is confused about...Ch. 7 - 110. In the absence of air resistance, a ball...Ch. 7 - 111. You’re on a rooftop and you throw one ball...Ch. 7 - 112. In the pulley system shown, block A has a...Ch. 7 - Prob. 113RCQCh. 7 - Prob. 114RCQCh. 7 - Prob. 115RCQCh. 7 - Prob. 116RCQCh. 7 - Prob. 117RCQCh. 7 - 118. Consider a bob attached by a string, a simple...Ch. 7 - Consider a satellite in a circular orbit above...Ch. 7 - 120. Consider the swinging-balls apparatus. If two...Ch. 7 - To combat wasteful habits, we often speak of...Ch. 7 - Prob. 122RCQ
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
- When a person feels that he is about to fall, he will often put out his hand to try to break the fall. Explain why this natural reaction usually leads to bruises or minor broken bones such as in the wrists instead of major broken bones such as the skull.arrow_forwardA woman wearing a stiletto heel shoes (heel pointed shoes) gets tired and will feel pain in her legs easily. Why so?arrow_forwardA screwdriver with a thick handle requires less force to operate than one with a skinny handle. Why?arrow_forward
- It is difficult to drive a nail into wooden block without supporting it. why?arrow_forwardA medical technician uses a pair of 0.125m long tweezers to remove a wood sliver from a patient. The technician is applying 5 N of squeezing force to the tweezers. If more than 1/5 lb of force is applied to the sliver, it will break and become difficult to remove. Assume the squeezing force is applied at 90 degrees to the tweezers. What is the mechanical advantage?arrow_forwardIf you count the tires on a large tractor-trailer that is unloading food at your local supermarket, you may be surprised to count 18 tires. Why so many tires? (Hint: Consider Project 1.)arrow_forward
- Which of the following? physical quantities is measured (in the units of (Kg/s² Select one: Torque Pressure O Friction force O Spring constant O Angular momentumarrow_forwardAfrican elephants are the largest land animals. They consume approximately 10% of their body weight in food each day, which for an adult male, can be 1000 lb. of vegetation! Their diet consists mostly of grasses, bamboo, tree bark, and fruit. They also like to dine on tree leaves. To reach them, they often stand up on their hind legs and extend their trunks (see the figure). The elephant in the figure is in equilibrium. The location of the elephant's center of mass is shown, and the axis of rotation has been chosen to correspond to the hip joint. The forces in the elephant's free-body diagram are shown, and there is a static friction force between the elephant's back feet and the ground. Use the following information and calculate the magnitude of the tension in the elephant's trunk T (m = 4540 kg, FN = rfs = 133 cm, rcg = 76.0 cm, r = 229 cm). Number +x Axis of rotation Units 60 165 30 W TTFN cg 10° Michael Poliza/Caters News Agencyarrow_forwardAn athlete strengthens her leg and knee by doing "leg curls." While sitting on a bench with the leg initially bent at the knee, she supports a weight with the foot. She then slowly raises the foot and lower leg, with the upper leg held stationary. Find the tension in the quadriceps tendon for the position shown in the figure below. (Let w = 225 N, D = 44 cm and d = 5.5 cm.) Please help thank youarrow_forward
- Using a screwdriver, you try to remove a screw from a piece of furniture, but cant get it to turn. To increase the chances of success, you should use a screwdriver that (a) is longer, (b) is shorter, (c) has a narrower handle, or (d) has a wider handle.arrow_forwardShow that when A+B=C then A2+B2+2ABcos , where is the angle between vectors A and B .arrow_forwardThe puck in Figure 10.25 has a mass of 0.120 kg. The distance of the puck from the center of rotation is originally 40.0 cm, and the puck is sliding with a speed of 80.0 cm/s. The string is pulled downward 15.0 cm through the hole in the frictionless table. Determine the work done on the puck. (Suggestion: Consider the change of kinetic energy.)arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
Classical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University
Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Classical Dynamics of Particles and Systems
Physics
ISBN:9780534408961
Author:Stephen T. Thornton, Jerry B. Marion
Publisher:Cengage Learning
Glencoe Physics: Principles and Problems, Student...
Physics
ISBN:9780078807213
Author:Paul W. Zitzewitz
Publisher:Glencoe/McGraw-Hill
Physics for Scientists and Engineers, Technology ...
Physics
ISBN:9781305116399
Author:Raymond A. Serway, John W. Jewett
Publisher: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: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Newton's First Law of Motion: Mass and Inertia; Author: Professor Dave explains;https://www.youtube.com/watch?v=1XSyyjcEHo0;License: Standard YouTube License, CC-BY