COLLEGE PHYSICS,TECH.UPDTE-W/MOD.MASTRG
3rd Edition
ISBN: 9780134583136
Author: Knight
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 7, Problem 5CQ
If you are using a wrench to loosen a very stubborn nut, you can make the job easier by using a “cheater pipe.” This is a piece of pipe that slides over the handle of the wrench, as shown in Figure Q7.4, making it effectively much longer. Explain why this would help you loosen the nut.
Figure Q7.4
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Q2. In Figure Q2, ropes AB and AC are tied at point A which is 5 m from the base of the tree,
O. The tensions in ropes AB and AC are 100 N and 120 N, respectively. The coordinates of
points B and C are given in the figure. Solve for the magnitude of moment about point o due
to the forces exerted on the tree.
y
B
(5, 0, 0) m
C (7,7,0) m
Figure Q2
The chewing muscle,
the masseter, is one of the stron-
gest in the human body. It is
attached to the mandible (lower
jawbone) as shown in Figure P8.33a. The jawbone is pivoted
about a socket just in front of the auditory canal. The forces
acting on the jawbone are equivalent to those acting on the
curved bar in Figure P8.33b. F. is the force exerted by the
food being chewed against the jawbone, T is the force of ten-
sion in the masseter, and R is the force exerted by the socket
on the mandible. Find T and R for a person who bites down
on a piece of steak with a force of 50.0 N.
3.50 cm
– 7.50 cm
Masseter
Mandible
Б
a
Figure P8.33
+,
F.
You use a wrench to turn a rusty nut. You place your hand at where the black dot is and apply a
force F = 110N at an angle 0 = 59 degrees. The distance from your hand to the center of nut d
= 30 cm. Calculate the torque in N. m your hand applies.
%3D
%3D
%3D
p.
0.
MacBook Pro
G Search or type URL
Chapter 7 Solutions
COLLEGE PHYSICS,TECH.UPDTE-W/MOD.MASTRG
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
An X-ray tube gives electrons constant acceleration over a distance of 15 cm. If their final speed is 1.2 107 ...
Essential University Physics (3rd Edition)
Explain all answers clearly, with complete sentences and proper essay structure if needed. An asterisk (*) desi...
Cosmic Perspective Fundamentals
What are the molar masses of molecular and atomic hydrogen, helium, oxygen, and nitrogen? What are their molecu...
College Physics
Suppose you have a gas containing hydrogen molecules and oxygen molecules, in thermal equilibrium. Which molecu...
An Introduction to Thermal Physics
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
- What is the magnitude of torque that would need to be applied to stop the motion of a 10-kg ball being swung at the end of a 10 m rope at 5 rad/s (i.e, angular momentum changes to 0) in 4 seconds? Select one: O a. 2500 Nm O b. 125 Nm O c. 250 Nm O d. 1250 Nm O e. 200 Nmarrow_forwardA 55-kg child sits on a 1.1-m radius playground merry-go-round without holding on to the rails. a. Someone pushes tangentially, resulting in a torque of 356 N m. How fast is the merry-go round moving (in m/s)? If the child begins to slip off the merry-go-round at this speed, what is the coefficient of friction between the child and the surface?arrow_forward2. A yo-yo consists of two solid disks, each of mass M and radius 3R. The two disks are connected by a rod of radius R and negligible mass. Assume the yo-yo starts at rest. a. Use the view on the right to draw the extended free body 3R diagram for the yo-yo. b. What is the moment of inertia of the yo-yo about an axis through its symmetry axis? м м c. Write Newton's 2nd law for the yo-yo. Choose your coordinate system carefully. d. Write the rotational form of Newton's 2nd law for the yo-yo. Treat the center of mass as being at the axis of rotation. Choose the positive direction of the rotation so a is positive. e. The point where the yoyo is momentarily at rest is where the string contacts the rod of the yo-yo. Use this to obtain a relation between the acceleration of the center of mass and the angular acceleration. f. Determine the linear acceleration of the yo-yo.arrow_forward
- Three small steel balls are connected by rigid, very light rods as shown in the figure. What is the moment of inertia if the object rotates about the x-axis? If we apply a force of 200. N to the most massive ball such that the object will rotate counterclockwise about the x-axis, what angular acceleration will result? 4.00 kg 0 2.00 kg 3.00 kg Y y = 3.00 m y = -2.00 m y = -4.00 marrow_forwardTwo blocks of wood (1 kg each) are connected with a 1m long rope. Another 1m long rope is tied to one of the blocks and connected to a rotating axle. The ropes can only hold 100N of tension before breaking. (Assume the ropes have no mass). !a. Derive equations for the tension in the ropes as a function of angular velocity.b. At what angular velocity will the rope break? c. Which rope breaks first?arrow_forwardThe large quadriceps muscle in the upper leg ter- Quadriceps - Tendon minates at its lower end in a - Tibia tendon attached to the upper end of the tibia (Fig. P8.35a). The forces on the lower leg when the leg is extended are modeled as in Figure P8.35b, where T is the force of ten- a sion in the tendon, w is the force of gravity acting on the lower leg, and F is the force of gravity acting on the foot. Find T when the ten- 25.0° T don is at an angle of 25.0° with the tibia, assuming that w = 30.0 N, F = 12.5 N, and the leg is extended at an angle 0 of 40.0° with the ver- Figure P8.35 tical. Assume that the center of gravity of the lower leg is at its center and that the tendon attaches to the lower leg at a point one-fifth of the way down the leg. 13arrow_forward
- 1P4 Two hoops or rings (I = MR^2) are centered, lying on a turntable. The smaller ring has radius = 0.050 m; the larger has radius = 0.10 m. Both have a mass of 3.0 kg. What is the total moment of inertia as the turntable spins? Ignore the mass of the turntable. choose 0.038 kgm^2 0.030 kgm^2 0.075 kgm^2 0.0075 kgm^2arrow_forwardIf you are using a rope to raise a tall mast, attaching the rope to the middle of the mast as in Q8.3a gives a very small torque about the base of the mast when the mast is at a shallow angle. You can get a larger torque by adding a pole with a pulley on top, as in Q8.3b. Draw a diagram showing all of the forces acting on the mast and explain why, for the same tension in the rope, adding this pole increases the torque on the mast.arrow_forwardThree rigid rods connect three small, identical balls in an isosceles triangle as shown. The mass of each rod is negligible. The mass of each ball is 300.0 grams. = 16.70⁰. a. Calculate the moment of inertia of the object for a rotation about the z-axis. Answer: 0.294 kg m². b. Calculate the moment of inertia of the object for a rotation about the y-axis. Answer: 1.034 kg m². 2.30 m 0 1.00 m 1.40 marrow_forward
- Q2. A thin square wooden slab was freely rotating on the frictionless surface (like an ice) with angular velocity i. The length of one side of the slab was L. The thickness of the slab was h. The density of the slab is p. Answer the following questions. ht Wi (a) What is the moment of inertia of this rotating slab? (b) What is the kinetic energy of this rotating slab?arrow_forwardlat ow 3. Three objects of equal mass, A, B, and C, are released from rest at the same instant from the same height on identical ramps. Objects A and B are both blocks, and they slide down their respective ramps without rotating. Object C rolls down the ramp without slipping. Its moment of inertia is unknown. All three objects are released from resti old lots B Objects A, B, and C are made of different materials, thus the coefficients of friction between the objects and their corresponding ramps are not necessarily the same. m = m, = mc Object A reaches the bottom of its ramp first, followed by objects B and C, which reach the bottom at the same instant. Rank the center-of-mass accelerations of objects A–C according to magnitude, from largest to smallest. If any objects have the same magnitude center-of-mass acceleration, state so explicitly. Explain. а. b. Rank the net forces exerted on objects A-C according to magnitude, from largest to smallest. If the magnitude of the net force on…arrow_forwarda. What is the moment of inertia of the door in the below problem?b. If you let go of the open door, what is its angular acceleration immediately afterward? A professor’s office door is 0.91 m wide, 2.0 m high, and 4.0 cm thick; has a mass of 25 kg; and pivots on frictionless hinges. A “door closer” is attached to the door and the top of the door frame. When the door is open and at rest, the door closer exerts a torque of 5.2 N ⋅ m. What is the least force that you need to apply to the door to hold it open?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
University Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSON
Introduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Lecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON
What is Torque? | Physics | Extraclass.com; Author: Extraclass Official;https://www.youtube.com/watch?v=zXxrAJld9mo;License: Standard YouTube License, CC-BY