Task id16413

A vertical axis is mounted in the elevator ceiling, to which a ball of mass m = 800 g is attached to a thread of length l = 40 cm. The axis rotates at a frequency of 90 rpm. Find the tension force of the thread T and the angle of inclination of the thread a to the vertical when the elevator moves upward with acceleration a = 3.0 m/s2. Neglect the mass of the thread.