Physics

Physics

Problem

A solid cylindrical disk of mass 2.5 kg2.5\,\text{kg} and radius 0.20 m0.20\,\text{m} is free to rotate about its central axle. A constant 1.6 N ⁣⋅ ⁣m1.6\,\text{N}\!\cdot\!\text{m} torque acts on the disk for a time interval tt. At t=0t=0 the disk’s angular velocity is ω0=4.0 rad/s\omega_0 = 4.0\,\text{rad/s}. a. Derive an expression for the disk’s angular velocity ω(t)\omega(t) as a function of time during the interval the torque is applied. b. Using your result from part (a), determine the disk’s angular velocity after 3.0 s3.0\,\text{s}. c. Starting from fundamental principles, obtain a rotational kinematic relation that is directly analogous to the translational equation v2=v02+2a Δxv^2 = v_0^2 + 2a\,\Delta x. Show each step of your derivation. d. Describe explicitly how each symbol in your rotational equation from part (c) corresponds to a symbol in the translational equation. Comment on any limitations of this one-to-one mapping.

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