24 Dec For the system of Prob. 18.99, show that (a Proble
For the system of Prob. 18.99, show that (a Problems ) the dynamic reaction at D is independent of the length 2a of the panel, (b) the ratio M1/M2 of the magnitudes of the couples exerted by the motors at A and C, respectively, is independent of the dimensions and mass of the panel and is equal to ω2 /2ω1 at any given instant.Prob. 18.99 A 48-kg advertising panel of length 2a = 2.4 m and width 2b = 1.6 m is kept rotating at a constant rate ω1 about its horizontal axis by a small electric motor attached at A to frame ACB. This frame itself is kept rotating at a constant rate ω2 about a vertical axis by a second motor attached at C to the column CD. Knowing that the panel and the frame complete a full revolution in 6 s and 12 s, respectively, express, as a function of the angle ω, the dynamic reaction exerted on column CD by its support at D.