& Rotating student A student sitting on a chair on a circular platform of negligible mass rotates freely on an air table at initial rotational speed 2.0 rad/s. The student**#x2019;s arms are initially extended with 6.0-kg dumbbells in each hand. As the student pulls her arms in towards her body, the dumbbells move from a distance of 0.80 m to 0.10 m from the axis of rotation. The initial rotational inertia of the student’s body (not including the dumbbells) with arms extended is 6.0 kg ·m 2 , and her final rotational inertia is 5.0 kg · m 2 . (a) Determine the student’s final rotational speed. (b) Determine the change of kinetic energy of the system consisting of the student together with the two dumbbells. (c) Determine the change in the kinetic energy of the system consisting of the two dumbbells alone without the student. (d) Determine the change of kinetic energy of the system consisting of the student alone without the dumbbells. (e) Compare the kinetic energy changes in parts (b) through (d).
& Rotating student A student sitting on a chair on a circular platform of negligible mass rotates freely on an air table at initial rotational speed 2.0 rad/s. The student**#x2019;s arms are initially extended with 6.0-kg dumbbells in each hand. As the student pulls her arms in towards her body, the dumbbells move from a distance of 0.80 m to 0.10 m from the axis of rotation. The initial rotational inertia of the student’s body (not including the dumbbells) with arms extended is 6.0 kg ·m 2 , and her final rotational inertia is 5.0 kg · m 2 . (a) Determine the student’s final rotational speed. (b) Determine the change of kinetic energy of the system consisting of the student together with the two dumbbells. (c) Determine the change in the kinetic energy of the system consisting of the two dumbbells alone without the student. (d) Determine the change of kinetic energy of the system consisting of the student alone without the dumbbells. (e) Compare the kinetic energy changes in parts (b) through (d).
& Rotating student A student sitting on a chair on a circular platform of negligible mass rotates freely on an air table at initial rotational speed 2.0 rad/s. The student**#x2019;s arms are initially extended with 6.0-kg dumbbells in each hand. As the student pulls her arms in towards her body, the dumbbells move from a distance of 0.80 m to 0.10 m from the axis of rotation. The initial rotational inertia of the student’s body (not including the dumbbells) with arms extended is 6.0 kg ·m2, and her final rotational inertia is 5.0 kg · m2. (a) Determine the student’s final rotational speed. (b) Determine the change of kinetic energy of the system consisting of the student together with the two dumbbells. (c) Determine the change in the kinetic energy of the system consisting of the two dumbbells alone without the student. (d) Determine the change of kinetic energy of the system consisting of the student alone without the dumbbells. (e) Compare the kinetic energy changes in parts (b) through (d).
At point A, 3.20 m from a small source of sound that is emitting uniformly in all directions, the intensity level is 58.0 dB. What is the intensity of the sound at A? How far from the source must you go so that the intensity is one-fourth of what it was at A? How far must you go so that the sound level is one-fourth of what it was at A?
Chapter 9 Solutions
College Physics: Explore And Apply, Volume 2 (2nd Edition)
Genetic Analysis: An Integrated Approach (3rd Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.