BIO The Kinetic Energy of Walking. If a person of mass M simply moved forward with speed V, his kinetic energy would be
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
UNIVERSITY PHYSICS UCI PKG
Additional Science Textbook Solutions
Physics (5th Edition)
College Physics (10th Edition)
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
University Physics Volume 1
Essential University Physics: Volume 1 (3rd Edition)
College Physics: A Strategic Approach (3rd Edition)
- A long, thin rod of mass m = 5.00 kg and length = 1.20 m rotates around an axis perpendicular to the rod with an angularspeed of 3.00 rad/s. a. What is the angular momentum of therod if the axis passes through the rods midpoint? b. What is theangular momentum of the rod if the axis passes through a pointhalfway between its midpoint and its end?arrow_forwardTo develop muscle tone, a woman lifts a 2.00-kg weight held in her hand. She uses her biceps muscle to flex the lower arm through an angle of 60.0°. (a) What is the angular acceleration if the weight is 24.0 cm from the elbow joint, her forearm has a moment of inertia of 0.250kg-m2 and the net force she exerts is 750 N at an effective perpendicular lever arm of 2.00 cm? (b) How much work does she do?arrow_forwardYour answer is partially correct. Energy of a Bullet Dissipated by Plywood. As part of a criminal investigation, you need to determine how much of a bullet's energy is dissipated by a 0.500-inch piece of plywood. You construct a device that consists of three disks that are separated by a distance d = 0.850 m and rotate on a common axis. The bullet is fired through the first disk (a few inches above its center), which is composed of a light plastic that has a negligible effect on the speed of the bullet. The bullet then passes through the second disk, which is composed of 0.500-inch plywood. Finally, the bullet strikes the third disk, where it becomes embedded. The disks rotate with an angular velocity of w = 86.0 rad/s. The angular displacement between holes in the first and second disks is A012 = 0.269 rad, and the angular displacement between the holes in the second and third disks is A023 = 0.286 rad. If the mass of the bullet is 12.0 g, find (a) the initial speed of the bullet and…arrow_forward
- Question 8. A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 414-mile trip in a typical midsize car produces about 1.32 × 109 J of energy. How fast would a 44.1-kg flywheel with a radius of 0.304 m have to rotate to store this much energy? Give your answer in rev/min. Ans: 343712.61 rev/minarrow_forwardA cord is wrapped around a pulley that is shaped like a disk of mass mand radius r. The cord's free end is connected to a block of mass M. The block starts from rest and then slides down an incline that makes an angle 0 with the horizontal as shown in Figure P10.48. The coefficient of kinetic friction between block and incline is u. (a) Use energy methods to show that the block's speed as a function of position d down the incline is 4Mgd(sin 0 – µ cos 0) т+ 2M (b) Find the magnitude of the acceleration of the block in terms of µ, m, M, g, and 0. m M Figure P10.48arrow_forwardA flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 324-mile trip in a typical midsize car produces about 1.01 x 10° J of energy. How fast would a 25.4-kg flywheel with a radius of 0.500 m have to rotate to store this much energy? Give your answer in rev/min. Number i Units rev/min varrow_forward
- A water molecule has initially zero kinetic energy (both rotational and translational). A collision with another water molecule provides the energy of 10−20 J. What is the ratio of kinetic translational and rotational energies of the water molecule assuming that the energy of the impact has redistributed among water’s rotations and translations?arrow_forwardA figure skater on ice with arms extended, spins at a rate of 2.5 rev/s. After he draws his arms in, he spins at 6.0 rev/s. By what factor does the skater's kinetic energy change when he draws his arms in? 2.4 1.0 0.42 0.12arrow_forwardThe figure shows a rigid assembly of a thin hoop (of mass m = 0.30 kg and radius R = 0.17 m) and a thin radial rod (of length L = 2R and also of mass m = 0.30 kg). The assembly is upright, but we nudge it so that it rotates around a horizontal axis in the plane of the rod and %3D %3D hoop, through the lower end of the rod. Assuming that the energy given to the assembly in the nudge is negligible, what is the assembly's angular speed about the rotation axis when it passes through the upside-down (inverted) orientation? Hoop Rod Rotation axis Number 9.23 Units rad/sarrow_forward
- A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 454-mile trip in a typical midsize car produces about 1.28 x 109 J of energy. How fast would a 20.6-kg flywheel with a radius of 0.461 m have to rotate to store this much energy? Give your answer in rev/min.arrow_forwardA car is traveling on the highway at a speed S. The body of the car, and driver, have a combined mass of M, the mass of each wheel is m, the radius of each wheel is r, and the rotational inertia of each wheel about the center of mass is IG. What is the total kinetic energy of the car?arrow_forwardMany machines employ cams for various purposes, such as opening and closing valves. In Figure P10.46, the cam is a circular disk of radius R with a hole of diameter R cut through it. As shown in the figure, the hole does not pass through the center of the disk. The cam with the hole cut out has mass M. The cam is mounted on a uniform, solid, cylindrical shaft of diameter R and also of mass M. What is the kinetic energy of the cam-shaft combination when it is rotating with angular speed ω about the shaft’s axis?arrow_forward
- College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPrinciples 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
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePhysics 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 Learning