Q- A disk of mass M₁ = 350 g and radius R₁ = 10 cm rotates about its symmetry axis at f_initial = 157 rpm. A second disk of mass M₂ = 261 g and radius R₂ = 6 cm, initially not rotating, is dropped on top of the first. Frictional forces act to bring the two disks to a common rotational speed f_final. (a) What is f_final? (b) In the process, how much kinetic energy is lost due to friction? (On request)

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