不 KE R₁ R₂ 9.79 Two metal disks, one with radius Figure P9.79 R₁ = 2.50 cm and mass M₁ =0.80 kg and the other with radius R₂ = 5.00 cm and mass M2 = 1.60 kg, are welded together and mounted on a frictionless axis through their common center (Fig. P9.79). (a) What is the total moment of inertia of the two disks? (b) A light string is wrapped around the edge of the smaller disk, and a 1.50 kg block is suspended from the free end of the string. If the block is released from rest at a distance of 2.00 m above the floor, what is its speed just before it strikes the floor? (c) Repeat part (b), this time with the string wrapped around the edge of the arger disk. In which case is the final speed of he block greater? Explain. 1.50 kg

不 KE R₁ R₂ 9.79 Two metal disks, one with radius Figure P9.79 R₁ = 2.50 cm and mass M₁ =0.80 kg and the other with radius R₂ = 5.00 cm and mass M2 = 1.60 kg, are welded together and mounted on a frictionless axis through their common center (Fig. P9.79). (a) What is the total moment of inertia of the two disks? (b) A light string is wrapped around the edge of the smaller disk, and a 1.50 kg block is suspended from the free end of the string. If the block is released from rest at a distance of 2.00 m above the floor, what is its speed just before it strikes the floor? (c) Repeat part (b), this time with the string wrapped around the edge of the arger disk. In which case is the final speed of he block greater? Explain. 1.50 kg

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter10: Rotation Of A Rigid Object About A Fixed Axis

Section: Chapter Questions

Problem 10.11OQ: A solid aluminum sphere of radius R has moment of inertia I about an axis through its center. Will...

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A solid aluminum sphere of radius R has moment of inertia I about an axis through its center. Will the moment of inertia about a central axis of a solid aluminum sphere of radius 2Rbe (a) 2I, (b) 4I, (c) 8I. (d) 16I. or (e) 32I?
A uniform disk of mass m = 10.0 kg and radius r = 34.0 cm mounted on a frictionlessaxle through its center, and initially at rest, isacted upon by two tangential forces of equalmagnitude F, acting on opposite sides of itsrim until a point on the rim experiences acentripetal acceleration of 4.00 m/s2 (Fig.P13.73). a. What is the angular momentumof the disk at this time? b. If F = 2.00 N, howlong do the forces have to be applied to thedisk to achieve this centripetal acceleration? FIGURE P13.73
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Two astronauts (Fig. P10.67), each having a mass M, are connected by a rope of length d having negligible mass. They are isolated in space, orbiting their center of mass at speeds v. Treating the astronauts as particles, calculate (a) the magnitude of the angular momentum of the two-astronaut system and (b) the rotational energy of the system. By pulling on the rope, one of the astronauts shortens the distance between them to d/2. (c) What is the new angular momentum of the system? (d) What are the astronauts new speeds? (e) What is the new rotational energy of the system? (f) How much chemical potential energy in the body of the astronaut was converted to mechanical energy in the system when he shortened the rope? Figure P10.67 Problems 67 and 68.
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A thin rod of length 2.65 m and mass 13.7 kg is rotated at anangular speed of 3.89 rad/s around an axis perpendicular to therod and through its center of mass. Find the magnitude of therods angular momentum.
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A thin rod of length 2.65 m and mass 13.7 kg is rotated at anangular speed of 3.89 rad/s around an axis perpendicular to therod and through one of its ends. Find the magnitude of the rodsangular momentum.
A solid cylinder of mass 2.0 kg and radius 20 cm is rotating counterclockwise around a vertical axis through its center at 600 rev/min. A second solid cylinder of the same mass and radius is rotating clockwise around the same vertical axis at 900 rev/min. If the cylinders couple so that they rotate about the same vertical axis, what is the angular velocity of the combination?
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Two particles of mass m1 = 2.00 kgand m2 = 5.00 kg are joined by a uniform massless rod of length = 2.00 m(Fig. P13.48). The system rotates in thexy plane about an axis through the midpoint of the rod in such a way that theparticles are moving with a speed of 3.00 m/s. What is the angular momentum of the system? FIGURE P13.48