1. If the mass of the 12-m boom is 10-kg. Find the forces exerted by supports A and B. 12 m 7 m 3 m A B 40 N 80 N 2. A disc rotates through 10 rad in 4 s. If the disk starts from rest, determine its angular velocity after 4 s. 3. If the system rotates perpendicular to the page at A and has angular speed of 500rpm, find a) rotational kinetic energy (KER) b) angular momentum (L). 2 kg 3 kg 120 cm 5 kg 250 cm 4 kg Note: question c) is not included c) How large a torque is needed to give it an angular acceleration of 4rev/s?? Ans: 675.47kg marad/$2 4. A steel rod 3.0 m long has a cross-sectional area of 0.60 cm^2 . It is hung by one end from a support, and a 600-kg milling machine is hung from its other end. Determine the stress on the rod and the resulting strain and elongation