Physics of Everyday Phenomena
9th Edition
ISBN: 9781259894008
Author: W. Thomas Griffith, Juliet Brosing Professor
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 8, Problem 2SP
(a)
To determine
The distance of the pivot point at the edge of the dock from the center of the plank.
(b)
To determine
The torque exerted by the weight of the plank about the pivot point at the edge of the dock.
(c)
To determine
The distance from the edge of the dock can the boy move until the plank is just on the verge of tripping.
(d)
To determine
How the boy tests the conclusion without falling in the water and explain the reason.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
The figure shows a uniform square plate from which four identical squares at the corners will be removed. Where is the center of gravity after the removal of squares 1, 2 nd 3?Immersive Reader
a) origin
b) first quadrant
c) third quadrant
d) x axis to the right of the origin
Two people carry a heavy electric motor by placing it on a light board 2.10 m long. One person lifts at one end with a force of 410 N , and the other lifts the opposite end with a force of 670 N
a) What is the weight of the motor?
b) Where along the board is its center of gravity located?
c) Suppose the board is not light but weighs 200 N , with its center of gravity at its center, and the two people each exert the same forces as before. What is the weight of the motor in this case?
d) Where is its center of gravity located?
Where is the center of gravity of a ring?
The biceps muscle exerts a vertical force of 7090 N on the lower arm. Calculate a. The torque about the axis of rotation through the elbow joint if the biceps and lower arm are perpendicular to each other b. If the lower arm is ° lower with respect to the horizontal. Assume that the muscle is attached 5.0 cm from the elbow.
Chapter 8 Solutions
Physics of Everyday Phenomena
Ch. 8 - Which units would not be appropriate for...Ch. 8 - Which units would not be appropriate for...Ch. 8 - A coin rolls down an inclined plane, gaining speed...Ch. 8 - The rate of rotation of an object is gradually...Ch. 8 - Is the rotational velocity of a child sitting near...Ch. 8 - Is the linear speed of a child sitting near the...Ch. 8 - If an object has a constant rotational...Ch. 8 - A ball rolls down an inclined plane, gaining speed...Ch. 8 - Which, if either, will produce the greater torque:...Ch. 8 - Which of the forces pictured as acting upon the...
Ch. 8 - The two forces in the diagram have the same...Ch. 8 - Is it possible to balance two objects of different...Ch. 8 - Is it possible for the net force acting on an...Ch. 8 - You are trying to move a large rock using a steel...Ch. 8 - Prob. 15CQCh. 8 - Prob. 16CQCh. 8 - Prob. 17CQCh. 8 - An object is rotating with a constant rotational...Ch. 8 - A tall crate has a higher center of gravity than a...Ch. 8 - Two objects have the same total mass, but object A...Ch. 8 - Is it possible for two objects with the same mass...Ch. 8 - Can you change your rotational inertia about a...Ch. 8 - A solid sphere and a hollow sphere made from...Ch. 8 - Is angular momentum always conserved? Explain.Ch. 8 - A metal rod is rotated first about an axis through...Ch. 8 - A child on a freely rotating merry-go-round moves...Ch. 8 - Moving straight inward, a large child jumps onto a...Ch. 8 - Is it possible for an ice skater to change his...Ch. 8 - Suppose you are rotating a ball attached to a...Ch. 8 - Does the direction of the angular-momentum vector...Ch. 8 - Does the direction of the angular momentum vector...Ch. 8 - Can a yo-yo be made to sleep if the string is tied...Ch. 8 - An ice skater is spinning counterclockwise about a...Ch. 8 - A pencil, balanced vertically on its eraser, falls...Ch. 8 - A top falls over quickly if it is not spinning,...Ch. 8 - When we shift gears on the rear-wheel gear of a...Ch. 8 - In what foot position do we exert maximum torque...Ch. 8 - If we move the chain to a larger sprocket on the...Ch. 8 - Suppose a merry-go-round is rotating at the rate...Ch. 8 - When one of the authors was a teenager, the rate...Ch. 8 - Suppose a disk rotates through eight revolutions...Ch. 8 - The rotational velocity of a merry-go-round...Ch. 8 - A bicycle wheel is rotationally accelerated at the...Ch. 8 - The rotational velocity of a spinning disk...Ch. 8 - Starting from rest, a merry-go-round accelerates...Ch. 8 - A force of 60 N is applied at the end of a wrench...Ch. 8 - A weight of 40 N is located a distance of 8 cm...Ch. 8 - A weight of 8 N is located 12 cm from the fulcrum...Ch. 8 - Two forces are applied to a merry-go-round with a...Ch. 8 - A net torque of 93.5 Nm is applied to a disk with...Ch. 8 - A wheel with a rotational inertia of 8.3 kgm2...Ch. 8 - A torque of 76 Nm producing a counterclockwise...Ch. 8 - Two 0.3-kg masses are located at either end of a...Ch. 8 - A mass of 0.75 kg is located at the end of a very...Ch. 8 - A uniform disk with a mass of 7 kg and a radius of...Ch. 8 - A student, sitting on a stool holds masses in each...Ch. 8 - A merry-go-round in the park has a radius of 1.5 m...Ch. 8 - Prob. 2SPCh. 8 - In the park, several children (having a total mass...Ch. 8 - A student sitting on a stool that is free to...
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 10cm uniform rod has a mass of 100g. Attached at its ends are 200g and 100g rubber balls. Where is the center of gravity of this rod-rubber balls system?arrow_forwardA thin rod has length L and total mass M lies along the x axis. (a) Suppose the rod is uniform. Find the position of the center of mass with respect to the left end of the rod in terms of L, M, and ?̂. (b) Now suppose the rod is not uniform but has a linear mass density that varies with the distance x from the left end according to the relation: ? = ? ?ଷ ?ଷ where λ0 is a constant and has SI units of kg/m. The total mass of the rod is still M. Find λ0 and the position of the center of mass with respect to the left end of the rod. Express your answer in terms of some or all of the following: L, M, and ?̂.arrow_forwardKatherine is attempting a biceps curl with a 100 N dumbbell. She is standing upright, and her forearm is horizontal. The moment arm of the dumbbell about Katherine’s elbow joint is 30 cm.a. What torque is created by the dumbbell about the elbow joint?b. If the elbow flexor muscles contract with a force of 1000 N and hold the barbell in static equilibrium, what is the moment arm of the elbow flexor muscles about the elbow joint?arrow_forward
- A. Who should sit farther from the center of a uniform seesaw, a 93-kg man or his 33-kg son, for the seesaw to remain in a horizontal position? Explain. B. Illustrate the figure and solve the problem by showing complete solution. Ella weighing 225 N sits at one end of a see-saw 4 m long. If Omar sits opposite her 150 cm away from the center, they balance each other. What is the weight of Omar? ( Disregard the weight of the seesaw)arrow_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_forwardA thin stick of mass 0.2 kg and length L=0.5m is attached to the rim of a metal disk of mass M=2.0kg and radius R=0.3m . The stick is free to rotate around a horizontal axis through its other end (see the following figure). (a) If the combinatin is related with the stick horizontal, what is the speed of the center of the disk when the stick is vertical? (b) What is the acceleration fo the center of the disk at the stick is released? (c) At the instant the stick passes through the vertical?arrow_forward
- You are attending a county fair with your friend from your physics class. While walking around the fairgrounds, you discover a new game of skill. A thin rod of mass M = 0.500 kg and length = 2.00 m hangs from a friction-free pivot at its upper end as shown in Figure P11.43. The front surface of the rod is covered with Velcro. You are to throw a Velcro-covered ball of mass m = 1.0 kg at the rod in an attempt to make it swing backward and rotate all the way across the top. The ball must stick to the rod at all times after striking it. If you cause the rod to rotate over the top position, you win a stuffed animal. Your friend volunteers to try his luck. He feels that the most torque would be applied to the rod by striking it at its lowest end. While he prepares to aim at the lowest point on the rod, you calculate how fast he must throw the ball to win the stuffed animal with this technique. Figure P11.43arrow_forwardA uniform rod of mass and length is held vertically by two strings of negligible mass, as shown below. (a) Immediately after the string is cut, what is the linear acceleration of the free end of the stick? (b) Of the middle of the stick?arrow_forwardA disk rolls up an inclined plane as shown in Figure P12.16, reaches point A, stops there momentarily, and then rolls down the inclined plane. Use the coordinate system shown to determine the direction of the angular velocity and the angular acceleration in each part of the motion as given below. If either one is zero, say so. Explain your answers. a. When the disk is going up the incline. b. At point A when the disk stops momentarily. c. When the disk is rolling down the incline FIGURE P12.16arrow_forward
- Figure CQ10.15 shows a side view of a childs tricycle with rubber tires on a horizontal concrete sidewalk. If a string were attached to the upper pedal on the far side and pulled forward horizontally, the tricycle would start to roll forward. (a) Instead, assume a siring is attached to the lower pedal on the near side and pulled forward horizontally as shown by A. Will the tricycle start to roll? If so, which way? Answer the same questions if (b) the string is pulled forward and upward as shown by B, (c) if the string is pulled straight down as shown by C, and (d) if the string is pulled forward and downward as shown by D. (e) What If? Suppose the string is instead attached to the rim of the front wheel and pulled upward and backward as shown by E. Which way does the tricycle roll? (f) Explain a pattern of reasoning, based on the figure, that makes it easy to answer questions such as these. What physical quantity must you evaluate? Figure CQ10.15arrow_forwardA projectile of mass m moves to the right with a speed vi (Fig. P10.81a). The projectile strikes and sticks to the end of a stationary rod of mass M, length d, pivoted about a frictionless axle perpendicular to the page through O (Fig. P10.81b). We wish to find the fractional change of kinetic energy in the system due to the collision. (a) What is the appropriate analysis model to describe the projectile and the rod? (b) What is the angular momentum of the system before the collision about an axis through O? (c) What is the moment of inertia of the system about an axis through O after the projectile sticks to the rod? (d) If the angular speed of the system after the collision is , what is the angular momentum of the system after the collision? (e) Find the angular speed after the collision in terms of the given quantities. (f) What is the kinetic energy of the system before the collision? (g) What is the kinetic energy of the system after the collision? (h) Determine the fractional change of kinetic energy due to the collision. Figure P10.81arrow_forwardThe fishing pole in Figure P8.3 makes an angle of 20.0 with the horizontal. What is the magnitude of the torque exerted by the fish about an axis perpendicular to the page and passing through the anglers hand if the fish pulls on the fishing line with a force F=1.00102N at an angle 37.0 below the horizontal? The force is applied at a point 2.00 m from the anglers hands. Figure P8.3arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning
University Physics Volume 1
Physics
ISBN:9781938168277
Author:William Moebs, Samuel J. Ling, Jeff Sanny
Publisher:OpenStax - Rice University
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning