Question

please answer C, and confirm that A and B are correct. (if you can)

Fa Fm (17.0" from ) a) (10 pts) Calculate the torque, about the Z-axis through the shoulder joint, due to the force of gravity on the dumbbell, Fa. (2, 23x9.80) dercos (43) Tdt d. Fa - (0.545)(COS(43)) td-(0.645X21.854) d-0.3986 m Td 11.91 Nm b) (10 pts) Calculate the torque, about Z-axis through the shoulder joint, due to the force of gravity on the mass of the arm, Fa. (3.89*9.80) dercos (43) (0.275)(C05 (43) -(0.2018 8.122) d-0.201 m Ta-7.66 Nm c) (10 pts) Assume that the deltoid muscle is providing the only biological torque about the Z-axis through the shoulder joint. Calculate the force, Fm, that the deltoid muscle must provide to keep the arm in its current position.

Answer 1

Part a) answer is not correct

d= 0.398m

$\tau_d = dF_d$

$\tau_d = dm_dg$

$\tau_d = (0.398)(2.23)(9.8)$

$\tau_d = 8.70 N-m$

part b ) It is correct

part c)

balancing the torques about the joint

$0.186(F_msin(17)) = \tau_d + \tau_a$