of mass m1and m2are connected by a massless string that passes over the pulley in FIGURE P12.65. The pulley turns on frictionless bearings. Mass m1slides on a horizontal, frictionless surface. Mass m2is released while the blocks are at rest.
a. Assume the pulley is massless. Find the acceleration of m1and the tension in the string. This is a Chapter 7 review problem.
b. Suppose the pulley has mass mpand radius R. Find the acceleration of m1and the tensions in the upper and lower portions of the string. Verify that your answers agree with part a if you set mp= 0.
Learn your wayIncludes step-by-step video
Chapter 12 Solutions
PHY SCIENTISTS&ENG V1 1-21 PKG W/MASTE
Additional Science Textbook Solutions
Cosmic Perspective Fundamentals
Modern Physics
Conceptual Integrated Science
The Cosmic Perspective Fundamentals (2nd Edition)
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
- A square plate with sides of length 4.0 m can rotate about an axle passing through its center of mass and perpendicular to the plate as shown in Figure P14.36. There are four forces acting on the plate at different points. The rotational inertia of the plate is 24 kgm2. Is the plate in equilibrium? FIGURE P14.36arrow_forwardA square plate with sides 2.0 m in length can rotatearound an axle passingthrough its center of mass(CM) and perpendicular toits surface (Fig. P12.53). There are four forces acting on the plate at differentpoints. The rotational inertia of the plate is 24 kg m2. Use the values given in the figure to answer the following questions. a. Whatis the net torque acting onthe plate? b. What is theangular acceleration of the plate? FIGURE P12.53 Problems 53 and 54.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
- Three forces are exerted on the disk shown in Figure P12.71,and their magnitudes are F3 = 2F2 = 2F1. The disks outer rimhas radius R, and the inner rim has radius R/2. As shown in thefigure, F1 and F3 are tangent to the outer rim of the disk, and F2 is tangent to the inner rim. F3 is parallel to the x axis, F2 is parallel to the y axis, and F1 makes a 45 angle with the negative x axis. Find expressions for the magnitude of each torque exertedaround the center of the disk in terms of R and F1. FIGURE P12.71 Problems 71-75arrow_forwardDisc jockeys (DJs) use a turntable in applying their trade, often using their hand to speed up or slow down a disc record so as to produce a desired change in the sound (Fig. P12.56). Suppose DJ Trick wants to slow down a record initially rotating clockwise (as viewed from above) with an angular speed of 33.0 rpm to an angular speed of 22.0 rpm. The record has a rotational inertia of 0.012 kgm2 and a radius of 0.15 m. a. What angular acceleration is necessary if he wishes to accomplish this feat in exactly 0.65 s with a constant acceleration? b. How many revolutions does the record go through during this change in speed? c. If DJ Trick applies a vertical force with his finger to the edge of the record, with what force must he push so as to slow the record in the above time? Assume the coefficient of kinetic friction between his finger and the record is 0.50, and ignore the mass of the finger. FIGURE P12.56arrow_forwardJohn is pushing his daughter Rachel in a wheelbarrow when it is stopped by a brick 8.00 cm high (Fig. P12.15). The handles make an angle of = 15.0 with the ground. Due to the weight of Rachel and the wheelbarrow, a downward force of 400 N is exerted at the center of the wheel, which has a radius of 20.0 cm. (a) What force must John apply along the handles to just start the wheel over the brick? (b) What is the force (magnitude and direction) that the brick exerts on the wheel just as the wheel begins to lift over the brick? In both parts, assume the brick remains fixed and does not slide along the ground. Also assume the force applied by John is directed exactly toward the center of the wheel.arrow_forward
- Review. A spool of wire of mass M and radius R is unwound under a constant force F (Fig. P10.42). Assuming the spool is a uniform, solid cylinder that doesnt slip, show that (a) the acceleration of the center of mass is 4F/3M and (b) the force of friction is to the right and equal in magnitude to F/3. (c) If the cylinder starts from rest and rolls without slipping, what is the speed of its center of mass after it has rolled through a distance d?arrow_forwardA disk with a radius of 4.5 m has a 100-N force applied to its outer edge at two different angles (Fig. P12.55). The disk has arotational inertia of 165 kg m2. a. What is the magnitude of the torque applied to the disk incase 1? b. What is the magnitude of the torque applied to the disk incase 2? c. Assuming the force on the disk is constant in each case,what is the magnitude of the angular acceleration applied tothe disk in each case? d. Which case is a more effective way of spinning the disk?Describe which quantity you are using to determine effectiveness and why you chose that quantity. FIGURE P12.55arrow_forwardA ceiling fan is rotating 245 times each minute. a. What is its frequency? b. What is its period of rotation? c. What is its angular velocity? d. When the fan is turned off, it slows down at 2.50 rad/s2. How long will it take the fan to stop?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning