A vertical rod AB is rigidly connected at its upper end B to a horizontal light rod, 15 cm in length. A pendulum bob of mass 20 g is tied to the of a light inextensible string which is fixed to the free end of the horizontal rod. The system is set into rotation about AB with n revolutions per second.
a) If the string makes an angle α=40° to the vertical, find
i) n, [0.7874 rev/s]
ii) the tension in the string. [0.2661 N]
b) Find the number of revolutions per second such that α=80° [1.796 rev/s]
c) Is it possible to make α=90° ? Given a reason. [No]
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[ 此貼被哈仔在2005-10-16 19:11重新編輯 ]
