108. (a) The angular speed ωassociated with Earth’s spin is = 2π/T, where T= 86400s (one day). Thus, 527.3 10 rad/s86400 s−π==×and the angular acceleration αrequired to accelerate the Earth from rest to in one day is= /T. The torque needed is then 372528(9.7 10 kg m )(7.3 10 rad/s)8.2 10 N m86400sIITτα−×⋅×==×⋅where we used ()()222463725.98 10kg 6.37 10 m9.7 10kg m55IMR××=×⋅for Earth’s rotational inertia.
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This note was uploaded on 05/17/2011 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.