Question

A3.1 RB Kinematics -Rotating reference fromes (Advanced) An athlete exercises his arm by raising the 8-kg mass m. The shoulder joint A is stationary. The distance AB is 300 mm, the distance BC is 400 mm, and the distance from C to the pulley is 340 mm. The angular velocities w 1.5 rad/s and 2 rad/s are constant. What are the velocity and acceleration of the weights?

Answer 1

A B --0.675i (m/s2). 2 -0.675i-(2)2 (0.4 cos 60° i + 0.4 sin 60°j) ー1 .4751-1 .386(m/s2). ac e (-1.475)-cos 30°) (1.386) (sin 30°) = 0.585 m/s This is the upward acceleration of the mass, so T-mg m (0.585). T (8)(9.81 + 0.585) = 83.2 N.