Question

L/2 dsin(0)7 Figure 4: Bending force diagram of model ofarm. Exercise 2: Figure 4 is an incomplete diagram of the three forces acting on the arm model that may cause bending around the central joint. The red arrows represent the three forces. Copy this diagram and complete it by doing the following: Label the red arrow representing the weight of the load held by the hand as "Wmg". Label the red arrow representing the tension in the bicep as "FB Mg. Label the red arrow representing the weight of the forearm as "Wmg Each of these forces applies a "torque", which is just the force multiplied by the perpendicular distance it acts about the joint. The perpendicular distance each force acts at is labelled in black in Figure 4 Using the perpendicular distances marked in Figure 4 In the model, what is the torque applied by the bicep muscle? ls it trying to turn the joint anticlockwise or clockwise? What is the torque applied by the weight of the forearm? Is it trying to turn the joint anticlockwise or clockwise? What is the torque applied by the load held in the hand? Is it trying to turn the joint anticlockwise or clockwise? At equilibrium no movement about the "elbow joint" occurs. So this means that all the applied torques add to zero. O Ifanticlockwise torques are in the positive direction, and clockwise torques are in the negative direction, write an equation using all your torques, showing they add to zero at equilibrium

Answer 1

a) CL dsin(0)7 Torque applied by bicep muscle-tension in bicep d sin e - Mqd Sins anticlockwise Torque applied by weight of forearm- weight of forearm * L2 m2) dlockwise Torque applied by load held in arm load held in arm L clockwise at equilibrium, total torque about joint -t0 2