A rigid turntable rotates about a central vertical axis

PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion

Problem

A rigid turntable rotates about a central vertical axis. The graph of its angular position θ\theta (in radians) versus time tt (in seconds) is described verbally as follows: • From t=0 st = 0\,\text{s} to t=5 st = 5\,\text{s}, θ\theta increases uniformly from 0 rad0\,\text{rad} to +10 rad+10\,\text{rad}. • From t=5 st = 5\,\text{s} to t=8 st = 8\,\text{s}, θ\theta remains constant at +10 rad+10\,\text{rad}. • From t=8 st = 8\,\text{s} to t=12 st = 12\,\text{s}, θ\theta decreases uniformly from +10 rad+10\,\text{rad} to +4 rad+4\,\text{rad}. Take the counter-clockwise (CCW) direction to be positive. (a) Describe qualitatively how the angular velocity ω\omega behaves during each of the three time intervals stated above. In your description include the sign of ω\omega and whether its magnitude is constant, zero, or changing. (b) On appropriately labeled axes with time on the horizontal and ω\omega on the vertical, sketch a possible ω\omega–versus–time graph that is consistent with the verbal description of θ(t)\theta(t). Clearly label the numerical values of ω\omega at the beginning and end of each interval. (c) Identify the time interval(s), if any, during which the turntable rotates clockwise (CW). Explain how you arrived at your answer.

Related theory

Browse the problem library