PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A yo-yo unwinds from rest as it descends. For the first 0.80s it experiences a constant angular acceleration of 6.0rad/s2 (counterclockwise, defined as positive). The string then becomes momentarily slack, and during the next 0.40s the yo-yo experiences a constant angular acceleration of −9.0rad/s2 due to the tension reversal as it rewinds.
(a) Determine the angular speed of the yo-yo at the instant the string first becomes slack.
(b) Calculate the angular speed of the yo-yo at the end of the 0.40s rewind interval.
(c) Find the net angular displacement of the yo-yo over the full 1.20s motion and state whether the yo-yo ends up above, below, or at the same angular position relative to its starting point. Justify your conclusion in one or two sentences.