(II) A merry-go-round has a mass of 1640 kg and a radius of 7.50 m. How much net work is required to accelerate it from rest to a rotation rate of 1.00 revolution per 8.00 s? Assume it is a solid cylinder.

A 4.00-kg mass and a 3.00-kg mass are attached to opposite ends of a very light 42.0-cm-long horizontal rod (Fig. 8–61). The system is rotating at angular speed w = 5.60 rad/s about a vertical axle at the center of the rod. Determine (a) the kinetic energy KE of the system, and (b) the net force on each mass. 3.00 kg 4.00 kg FIGURE 8-61 Problem 87.

A child of mass m stands at the center of a merry-go-round with moment of inertia Io and radius R that can rotate freely about a frictionless axle at its center. A group of her friends spins it up to an angular velocity wo counterclockwise while she stands at the center. The child then walks to the edge of the merry-go-round. (i) What is the angular velocity of the merry-go-round when she reaches the edge? (ii) If she then jumps off with speed vo at the angle 0, what is the final angular velocity of the merry-go-round? Law Application R (overhead view) 0 VO

(II) A small 350-gram ball on the end of a thin, light rodis rotated in a horizontal circle of radius 1.2 m. Calculate(a) the moment of inertia of the ball about the center ofthe circle, and (b) the torque needed to keep the ballrotating at constant angular velocity if air resistance exertsa force of 0.020 N on the ball. Ignore air resistance onthe rod and its moment of inertia.

MY NOTES ASK A car initially traveling at 24.2 m/s undergoes a constant negative acceleration of magnitude 1.70 m/s after its brakes are applied. (a) How many revolutions does each tire make before the car comes to a stop, assuming the car does not skid and the tires have radii of 0.345 m? X rev (b) What is the angular speed of the wheels when the car has traveled half the total distance? X rad/s Submit Answer 10. [2/2 Points] DETAILS PREVIOUS ANSWERS SERCP11 7.4.P.020. MY NOTES ASK YC Human centrifuges are used to train military pilots and astronauts in preparation for hiigh-g maneuvers. A trained, fit person wearing a g-suit can withstand accelerations up (88.2 m/s) without losing consciousness.