College Physics: A Strategic Approach (3rd Edition)
3rd Edition
ISBN: 9780321879721
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 7, Problem 10CQ
To determine
To describe: The technique to find out the center of gravity of an irregularly-shaped object by hanging itfreely.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
B As shown in Figure 1, two people of the same height are holding up a box attached to a pole.
The center of gravity of the pole and the box is located at point G. The pole is supported at
points A and B. The pole and the box do not change form.
A
4
1 + cos 0
1 - cos 0
G
1 sin
1+ sin 0
m
Figure 1
B
1 - cos
1 + cos 0
1+tan 0
1 tan 0
FA
Q2 As shown in Figure 2, the two people are now standing on a slope inclined by angle
(< from the horizontal. The person supporting the upper end at A exerts a force
of magnitude of FA vertically upward. The person supporting the lower end at B exerts a
force of magnitude of FB vertically upward. What is the value of the ratio
0-6 below choose the correct answer.
FAQ
FB
B
Figure 2
(33)
0
1+ sin 8
1 - sin 0
B
1
tan 0
1 + tan 0
FB
From
2
The two ends of the dumbbell shown below are made of the same material. Is the dumbbell’s center of gravity at point 1, 2, or 3? Explain.
What is the center of gravity of the solid formed when the plane region
bounded by y = x^3 and the lines y = 0 and x = 2 is revolved about x = 2 ?
O (-2, 10/7)
O (2,10/7)
(10/7,-2)
O (10/7,2)
ONA
Chapter 7 Solutions
College Physics: A Strategic Approach (3rd Edition)
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
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) When opening a door, you push on it perpendicularly with a force of 55.0 N at a distance of 0.850 m from the hinges. What torque are you exerting relative to the hinges? (b) Does it matter if you push at the same height as the hinges? There is only one pair of hinges.arrow_forwardA 215-kg robotic arm at an assembly plant is extended horizontally (Fig. P14.32). The massless support rope attached at point B makes an angle of 15.0 with the horizontal, and the center of mass of the arm is at point C. a. What is the tension in the support rope? b. What are the magnitude and direction of the force exerted by the hinge A on the robotic arm to keep the arm in the horizontal position? FIGURE P14.32arrow_forward(a) Calculate the angular momentum of Earth in its orbit around the Sun. (b) Compare this angular momentum with the angular momentum of Earth about its axis.arrow_forward
- Shown are two thin beams joined at right angles. The vertical beam is 15.0 kg and 1.00 m long and the horizontal beam is 25.0 kg and 2.00 m long.a. Find the center of gravity of the two joined beams. Express your answer in the form (x, y), taking the origin at the corner where the beams join.b. Calculate the gravitational torque on the joined beams about an axis through the corner. The beams are seen from the side.arrow_forwardWhen you bend over, a series of large muscles, the erector spinae, pull on your spine to hold you up. Figure shows a simplified model of the spine as a rod of length L that pivots at its lower end. In this model, the center of gravity of the 320 N weight of the upper torso is at the center of the spine. The 160 N weight of the head and arms acts at the top of the spine. The erector spinae muscles are modeled as a single muscle that acts at an 12° angle to the spine. Suppose the person shown bends over to an angle of 30° from the horizontal. a. What is the tension in the erector muscle? Hint: Align your x-axis with the axis of the spine.b. A force from the pelvic girdle acts on the base of the spine. What is the component of this force in the direction of the spine? (This large force is the cause of many back injuries).arrow_forwardThe two ends of the barbell shown are made of the same material. Which of the points shown is at the barbell’s center of gravity?arrow_forward
- B1arrow_forwardA. Three identical coins, labeled A, B, and C in the figure, lie on three corners of a square 10.0 cm on a side. Determine the x coordinate of each coin, xA, xB, and xC B. Determine the y coordinate of each coin described in Part A: yA, yB, and yC. C. Determine the x and y coordinates xcg and ycg of the center of gravity of the three coins described in Part A.arrow_forwardWe can model a pine tree in the forest as having a compact canopy at the top of a relatively bare trunk. Wind blowing on the top of the tree exerts a horizontal force, and thus a torque that can topple the tree if there is no opposing torque. Suppose a tree's canopy presents an area of 9.0 m2m2 to the wind centered at a height of 7.0 mm above the ground. (These are reasonable values for forest trees. *Part A If the wind blows at 6.5 m/sm/s, what is the magnitude of the drag force of the wind on the canopy? Assume a drag coefficient of 0.50 and the density of air of 1.2 kg/m3kg/m3. Express your answer with the appropriate units. *Part B What torque does this force exert on the tree, measured about the point where the trunk meets the ground? Express your answer with the appropriate units.arrow_forward
- Item 6 A 4.80-m-long, 500 kg steel uniform beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 70 kg construction worker stands at the far end of the beam. Part A What is the magnitude of the torque about the bolt due to the worker and the weight of the beam? T = VE ΑΣΦ ? N.marrow_forwardThe arm in Figure P8.17 weighs 41.5 N. The force of gravity acting on the arm acts through point A. Determine the magnitudes of the tension force F, in the deltoid muscle and the force F, exerted by the shoulder on the humerus (upper- arm bone) to hold the arm in the position shown. F, 12° F, '0.080 m -0.290 m Figure P8.17arrow_forwardA 5.4 kg cat and a 2.5 kg bowl of tuna fish are at opposite ends of the 4.0-m-long seesaw. (Figure 1) You may want to review (Pages 312 - 314). Figure 2.0 m 2.0 m 1 of 1 Part A How far to the left of the pivot must a 4.0 kg cat stand to keep the seesaw balanced? Express your answer to two significant figures and include the appropriate units. d = Value Submit μA Provide Feedback Request Answer Unitsarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
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...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
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
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