Concept explainers
A light, flexible rope is wrapped several times around a hollow cylinder, with a weight of 40.0 N and a radius of 0.25 m, that rotates without friction about a fixed horizontal axis. The cylinder is attached to the axle by spokes of a negligible moment of inertia. The cylinder is initially at rest. The free end of the rope is pulled with a constant force P for a distance of 5.00 m, at which point the end of the rope is moving at 6.00 m/s. If the rope does not slip on the cylinder, what is P?
Trending nowThis is a popular solution!
Chapter 9 Solutions
University Physics with Modern Physics (14th Edition)
Additional Science Textbook Solutions
Sears And Zemansky's University Physics With Modern Physics
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
College Physics (10th Edition)
Conceptual Integrated Science
Physics: Principles with Applications
- As shown in Figure OQ10.9, a cord is wrapped onto a cylindrical reel mounted on a fixed, frictionless, horizontal axle. When does the reel have a greater magnitude of angular acceleration? (a) When the cord is pulled down with a constant force of 50 N. (b) When an object of weight 50 N is hung from the cord and released. (c) The angular accelerations in parts (a) and (b) are equal. (d) It is impossible to determine. Figure OQ10.9arrow_forwardConsider the disk in Problem 71. The disks outer rim hasradius R = 4.20 m, and F1 = 10.5 N. Find the magnitude ofeach torque exerted around the center of the disk. FIGURE P12.71 Problems 71-75arrow_forwardA weight with mass ?w=250 g is tied to a piece of thread wrapped around a spool, which is suspended in such a way that it can rotate freely. When the weight is released, it accelerates toward the floor as the thread unwinds. Assume that the spool can be treated as a uniform solid cylinder of radius ?=4.00 cm and mass ?s=100 g. Find the magnitude of the acceleration of the weight as it descends. Assume the thread has negligible mass and does not slip or stretch as it unwinds. Find the tension in the thread.arrow_forward
- A beam, uniform in mass, M = 21 kg and length L = 24 m, hangs by a cable supported at point B, and rotates without friction around point A. On the end far of the beam, an object of mass m = 6 kg is hanging. The beam is making an angle of θ = 25° at point A with respect to the + x-axis. The cable makes an angle φ = 29° with respect to the - x-axis at B. Assume ψ = θ + φ. What is the horizontal force Sx the wall exerts on the beam at point A in terms of the tension T? What is the vertical force Sy that the wall exerts on the beam at point A in terms of the tension T, given parameters, and variables available in the palette?arrow_forwardThe circular disk of 270-mm radius has a mass of 36 kg with centroidal radius of gyration k⎯⎯k¯ = 235 mm and has a concentric circular groove of 105-mm radius cut into it. A steady force T is applied at an angle θ to a cord wrapped around the groove as shown. If T = 59 N, θ = 29°, μs = 0.08, and μk = 0.07, determine the angular acceleration α of the disk, the acceleration a of its mass center G, and the friction force F which the surface exerts on the disk. The angular acceleration α is positive if counterclockwise, negative if clockwise; the acceleration a is positive if to the right, negative if to the left; and the friction force F is positive if to the right, negative if to the left..arrow_forwardA beam, uniform in mass, M = 51 kg and length L = 6 m, hangs by a cable supported at point B, and rotates without friction around point A. On the end far of the beam, an object of mass m = 12 kg is hanging. The beam is making an angle of θ = 15° at point A with respect to the + x-axis. The cable makes an angle φ = 25° with respect to the - x-axis at B. Assume ψ = θ + φ. Part (a) Select the correct free body diagram. In the figure the tension is T, horizontal and vertical components of the support force are Sx and Sy, FB is the weight of the beam, and Fm is the weight of the mass. Part (b) Find an expression for the lever arm for the weight of the beam, lB, about the point A? Part (c) Find an expression for the lever arm for the weight of the mass, lm? Part (d) Write an expression for the magnitude of the torque about point A created by the tension T. Give your answer in terms of the tension T and the other given parameters and trigonometric functions. Part (e) What is the…arrow_forward
- A 13.0-m length of hose is wound around a reel, which is initially at rest. The moment of inertia of the reel is 0.560 kg-m2, and its radius is 0.160 m. When turning, friction at the axle exerts a torque of magnitude 3.20 N-m on the reel. If the hose is pulled so that the tension in it remains a constant 25.0 N, how long does it take to completely unwind the hose from the reel? Neglect the mass of the hose, and assume that the hose unwinds without slipping.arrow_forwardThis problem describes one experimental method for determining the moment of inertia of an irregularly shaped object such as the payload for a satellite. As shown a counterweight of mass m suspended by a cord wound around a spool of radius r, forming part of a turntable supporting the object. The turntable can rotate without friction. When the counterweight is released from rest, it descends through a distance h, acquiring a speed υ. Show that the moment of inertia I of the rotating apparatus (including the turntable) is mr2(2gh/υ2 - 1).arrow_forwardA (Yo-Yo) of mass m has an axle of radius b and spool of radius R. It's 1 moment of inertia be taken to be I = mR? and the thickness of the string %3D 2.arrow_forward
- A 17.0-m length of hose is wound around a reel, which is initially at rest. The moment of inertia of the reel is 0.490 kg-m², and its radius is 0.150 m. When turning, friction at the axle exerts a torque of magnitude 3.20 N-m on the reel. If the hose is pulled so that the tension in it remains a constant 26.0 N, how long does it take to completely unwind the hose from the reel? Neglect the mass and the thickness of the hose, and assume that the hose unwinds without slipping.arrow_forwardAn object of 50.5 N is attached to the free end of a light string wrapped around a reel with a radius of 0.250 m and mass of 3.00 kg. The reel is a solid disk, free to rotate in a vertical plane about the horizontal axis passing through its center. The suspended object is released 5.50 m above the floor.(a) Determine the tension in the string, the acceleration of the object, and the speed with which the object hits the floor.arrow_forwardWhile exercising in a fitness center, a man lies face down on a bench and lifts a weight with one lower leg by contracting the muscles in the back of the upper leg. The weight has mass 10.5 kg, and is a distance of 28.0 cm from the knee joint. The moment of inertia of the lower leg is 0.900 kg m² , the muscle force is 1410 N, and its effective perpendicular lever arm is 3.40 cm. Find the magnitude of the angular acceleration a of the weight. a = rad/s? How much work W is done if the leg rotates through an angle of 15.0° with a constant force exerted by the muscle? W = Jarrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning