The maximum mass m that a person can hold in a hand when the arm is positioned w
ID: 2253805 • Letter: T
Question
The maximum mass m that a person can hold in a hand when the arm is positioned with a 105?angle at the elbow as shown in (Figure 1) is 23kg . Assume the forearm and hand have a total mass of 2.0 kgwith a CG that is 15 cmfrom the elbow, and that the biceps muscle attaches 5.0 cmfrom the elbow. What is the maximum force (Fmax) that the biceps muscle exerts on the forearm?
Explanation / Answer
180 - 105 = 75 deg
Moments balance:
23*g*35 + 2*g*15 = F_max*sin75 *5
Putting g = 9.81 m/s^2 we get
F_max = 1696.06 N