radius of 1.80 m and it is rotating with an angular velocity of 0.500 rev/s.  What is its angular velocity after a 22.0-kg child (who is initially at rest) gets onto it by grabbing its outer edge?  (You can approximate the child as a point mass). (Hint: here you'll need to use the conservation of angular momentum.) a. 0.683 rev/s b. 0.415 rev/s c. 0.366 rev/s d. 0.129 rev/s

Suppose a star has a mass three times that of our sun (that is, the star's mass will be 6 x 1030 kg) and starts out as a sphere with an initial radius several times larger than our sun (3.48 x10° m). It is initially spinning with one revolution every 12 days. What is its angular momentum, in kg m2/s?

A 42.7 kg person starts at the center of a frictionless rotating merry-go-round that has a radius of 2.72 m and a mass of 60.5 kg that is uniformly distributed throughout. If the initial angular velocity is 5.39 rad/s, what is the tangential velocity of the person when they move to the edge of the merry-go-round?

Conceptual Example 14 provides useful background for this problem. A playground carousel is free to rotate about its center on frictionless bearings, and air resistance is negligible. The carousel itself (without riders) has a moment of inertia of 125 kg-m². When one person is standing on the carousel at a distance of 1.50 m from the center, the carousel has an angular velocity of 0.600 rad/s. However, as this person moves inward to a point located 1.01 m from the center, the angular velocity increases to 0.800 rad/s. What is the person's mass? m = i

A merry-go-round modeled as a disk of mass M = 7.50 x 10- kg and radius R = 2.10 m is rotating in a horizontal plane about a frictionless vertical axle (see figure). (a) After a student with mass m = 82.0 kg jumps onto the merry-go-round, the system's angular speed decreases to 2.05 rad/s. If the student walks slowly from the edge toward the center, find the angular speed of the system when she reaches a point 0.470 m from the center. 5.88 rad/s (b) Find the change in the system's rotational kinetic energy caused by her movement to the center. 2073.05 (c) Find the work done on the student as she walks to r = 0.470 m. -2073.05 Your response differs from the correct answer by more than 100%. J

Consider the 13 kg motorcycle wheel shown in the figure. Assume it to be approximately a ring with an inner radius of 0.285 m and an outer radius of 0.325 m. The motorcycle is on its center stand, so that the wheel can spin freely. If the drive chain exerts a force of 2200 N at a radius of 4.95 cm, what is the angular acceleration of the wheel, in radians per square second?  What is the tangential acceleration, in meters per square second, of a point on the outer edge of the tire?   How long, in seconds, starting from rest, does it take to reach an angular velocity of 89.5 rad/s?

A 82.1 kg horizontal circular platform rotates freely with no friction about its center at an initial angular velocity of 1.69 rad/s. A monkey drops a 8.95 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 20.1 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 1.95 m.