In a classroom demonstration a student sits on a stool and holds 5 kg masses in each hand as he rotates with the stool and weights about a vertical axis. With his arms outstretched, as shown, he rotates at 0.25 rev/s. When he brings the weights in near the axis of rotation he rotates at 1.0 rev/s. Regarding the stool, the weights, and the student as a single system, what is the ratio of the system's final moment of inertia, Ienal to its initial moment of inertia, Imia? (The initial configuration is with his arms outstretched.) O Ianat /Inial - 1/4 O lenal/ntial - 16 O Ia/Inrial = 1/16 O Ianal/ntia-4 O lenal /Intial = 1/3

Please refer to the picture to help answer the questions. A ice skater goes into a spin standing vertically with his arms outstretched horizontally. We can crudely model his torso and legs as a cylinder with radius 0.1m and mass 52 kg and each arm is a rod with mass 4 kg and length 0.9 m. The skater will initially spin at 2.0 rad/s.  Question 1: what is the moment of inertia of the skater's torso and legs. Please answer in kg m^2. Question 2: What is the moment of inertia of one of the skater's arms? Please answer in kg m^2. Question 3: What is the total moment of inertia of the skater? Please answer in kg m^2

What is the angular momentum of a 0.315 kg ball rotating on the end of a thin string in a circle of radius 1.10 m at an angular speed of 12.0 rad/s ? Express your answer using three significant figures and include the appropriate units.

A horizontal circular platform rotates counterclockwise about its axis at the rate of 0.941 rad/s. You, with a mass of 70.9 kg, walk clockwise around the platform along its edge at the speed of 1.03 m/s with respect to the platform. Your 21.1 kg poodle also walks clockwise around the platform, but along a circle at half the platform's radius and at half your linear speed with respect to the platform. Your 17.3 kg mutt, on the other hand, sits still on the platform at a position that is 3/4 of the platform's radius from the center. Model the platform as a uniform disk with mass 90.9 kg and radius 1.83 m. Calculate the total angular momentum of the system. total angular momentum: 206.521 kg · m²/s