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 (in radians) versus time t (in seconds) is described verbally as follows:
• From t=0s to t=5s, θ increases uniformly from 0rad to +10rad.
• From t=5s to t=8s, θ remains constant at +10rad.
• From t=8s to t=12s, θ decreases uniformly from +10rad to +4rad.
Take the counter-clockwise (CCW) direction to be positive.
(a) Describe qualitatively how the angular velocity ω behaves during each of the three time intervals stated above. In your description include the sign of ω and whether its magnitude is constant, zero, or changing.
(b) On appropriately labeled axes with time on the horizontal and ω on the vertical, sketch a possible ω–versus–time graph that is consistent with the verbal description of θ(t). Clearly label the numerical values of ω 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.