60. When some stars use up their fuel, they undergo a catastrophic explosion called a supernova. This explosion blows much or all of the star's mass outward, in the form of a rapidly expanding spherical shell. As a simple model of the supernova process, assume that the star is a solid sphere of radius R that is initially rotating at 2.0 revolutions per day. After the star explodes, find the angular velocity, in revolutions per day, of the expanding supernova shell when its radius is 4.0R. Assume that all of the star's original mass is contained in the shell.

60. When some stars use up their fuel, they undergo a catastrophic explosion called a supernova. This explosion blows much or all of the star's mass outward, in the form of a rapidly expanding spherical shell. As a simple model of the supernova process, assume that the star is a solid sphere of radius R that is initially rotating at 2.0 revolutions per day. After the star explodes, find the angular velocity, in revolutions per day, of the expanding supernova shell when its radius is 4.0R. Assume that all of the star's original mass is contained in the shell.

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

See similar textbooks

Similar questions

Modern wind turbines generate electricity from wind power. The large, massive blades have a large moment of inertia and carry a great amount of angular momentum when rotating. A wind turbine has a total of 3 blades. Each blade has a mass of m = 5500 kg distributed uniformly along its length and extends a distance r = 44 m from the center of rotation. The turbine rotates with a frequency of f = 15 rpm. Calculate the angular momentum of the wind turbine, in units of kilogram meters squared per second.
A solid disk rotates in the horizontal plane at an angular velocity of 4.20 × 10-2 rad/s with respect to an axisperpendicular to the disk at its center. The moment of inertia of the disk is 0.14 kg.m2. From above, sand is droppedstraight down onto this rotating disk, so that a thin uniform ring of sand is formed at a distance of 0.40 m from the axis.The sand in the ring has a mass of 0.50 kg. After all the sand is in place, what is the angular velocity of the disk?
While placing a compact disc into a CD player, you notice a small chip on its edge. You attempt to play the CD anyway by placing the CD into the player's deck with the chip at ?0=15.2∘θ0=15.2∘ as measured from the +?+x‑axis. The CD begins to rotate with angular acceleration ?=2.31 rad/s2.α=2.31 rad/s2. If the CD has been spinning for ?=3.51 st=3.51 s and the disc has a radius of ?=6.00 cm,r=6.00 cm, what are the ?–?x–y coordinates of the chip after this time, assuming the center of the disc is located at (0.00,0.00)
A 3.8-mm-diameter merry-go-round is rotating freely with an angular velocity of 0.80 rad/s. Its total moment of inertia is 1300 kg⋅m2. Four people standing on the ground, each of mass 61 kg, suddenly step onto the edge of the merry-go-round. What is the angular velocity of the merry-go-round now? What if the people were on it initially and then jumped off in a radial direction (relative to the merry-go-round)?
You are riding your bicycle down the road and decide to stop to take in the scenery. Initially, your bicycle tires are rotating at a frequency of 7 times per second. If it takes your bicycle 50 revolutions to come to a full stop, what is the magnitude of the angular acceleration (assume your acceleration is constant). Give your answer in units of radians per second squared
A bug is on the surface of a small wheel, which is a solid disk.
Assume Earth is approximately a uniform, solid sphere that has a mass of 5.98×10^24 kg and a radius of 6.38×10^6 m. Calculate the angular momentum ?? of Earth as it spins on its central axis once each day. ??= kg·m2/s
1. The horizontal circular platform weighs 500 lb and has a radius of gyration of kz = 8 ft from the z-axis passing through O. The platform is free to rotate about the z-axis and is initially at rest. A person having a weight of 150 lb begins to run along the edge in a circular path of radius 10 ft. If they maintain a speed of 4 ft/s relative to the platform, determine the angular velocity of the 10 ft platform. Neglect friction. I don't think we have dealt with relative velocity in this context, but it follows our earlier relative velocity treatment. Here all speeds are in the t-direction. vp is the speed of the person, and vp is the speed of the disk at the location of the person. Then vp = vp + Vp/D, same as before. You are given vpp = 4 ft/s.
The figure shows a device that can be used to measure the speed of a bullet. The device consists of two rotating disks, separated by a distance of d = 0.872 m, and rotating with an angular speed of 101 rad/s. The bullet first passes through the left disk and then through the right disk. It is found that the angular displacement between the two bullet holes is = 0.268 rad. From these data, determine the speed of the bullet. Number IN Bullet Units Motor
A uniform thin rod of length 0.73 m and mass 3.0 kg can rotate in a horizontal plane about a vertical axis through its center. The rod is at rest when a 4.4 g bullet traveling in the rotation plane is fired into one end of the rod. As viewed from above, the bullet's path makes angle 0 = 60° with the rod. If the bullet lodges in the rod and the angular velocity of the rod is 11.0 rad/s immediately after the collision, what is the bullet's speed just before impact? Ахis Number Units
A 87.9 kg horizontal circular platform rotates freely with no friction about its center at an initial angular velocity of 1.53 rad/s. A monkey drops a 8.97 kg bunch of bananas vertically onto the platform. They hit the platform at 4/5 of its radius from the center, adhere to it there, and continue to rotate with it. Then the monkey, with a mass of 20.7 kg, drops vertically to the edge of the platform, grasps it, and continues to rotate with the platform. Find the angular velocity of the platform with its load. Model the platform as a disk of radius 1.65 m.