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11/21 Rotation and Torque. Today: Start Rotational Dynamics HW “Torque with Acceleration” Due Monday 11/25 MCAT Review Class Orientation Thursday (tonight) at 7:30 pm Haugen Lecture Hall, Med School For details attend tonight or contact: Kim Ruit: 777-2749 kim_ruit@und.nodak.edu.
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11/21 Rotation and Torque • Today: Start Rotational Dynamics • HW “Torque with Acceleration” Due Monday 11/25 • MCAT Review Class OrientationThursday (tonight) at 7:30 pm Haugen Lecture Hall, Med SchoolFor details attend tonight or contact: Kim Ruit: 777-2749 kim_ruit@und.nodak.edu
Displacement, x (distance moved) Average Velocity, vave (average over time) Instantaneous Velocity, v (at a particular time) Change in Velocity, v (speeding up or slowing down) Acceleration, a (how much the velocity changes each second) Force: N, W, f, T For Translation we have:
Displacement, (angular distance moved) Average Angular Velocity, ave (time average) Instantaneous Angular Velocity, (at a particular time) Change in Angular Velocity, (speeding up or slowing down) Angular Acceleration, (how much changes each second) For Rotation we have: Torque: Nr, Wr, fr, Tr
vave = x/t ave = /t a = v/t = /t t = 2x/a t = 2/ It’s all the same! About Distance About Angles The quantity “I” is the “moment of inertia” and will be given to you. Fnet = ma net = I KET = 1/2mv2 KER = 1/2I2 WorkT = F x WorkR =
Example A wheel with I = 5kg m2, is mounted on a frictionless axle. A rope wrapped around its outer rim is pulled with a force T = 50N for a distance of 2m. Find everything, starting with . r = 0.5m 2m Not necessarily a disk or ring, the quantity “I” contains that information