Biomechanics Question Use 4kg as the mass , the 6kg was a typo! Kin2062 - Assign
ID: 1795252 • Letter: B
Question
Biomechanics Question
Use 4kg as the mass , the 6kg was a typo!
Kin2062 - Assignment 11B.pdf (page 2 of 3) Edited ' Q Search 2. A motion analysis and force plate system installed in a staircase were used to measure limlb kinematics, external forces acting on the tibia (i.e. ground reaction force and limb mass), and moment arms at a specific instant during stair climbing. Assume the lower limb mass has a mass of 6kg and a moment of inertia of 0.41 kg·m" (relative to the knee center). At the instant shown below, the lower limb rapidly decelerates at -17rad/s. a) Calculate the inertial moment of the lower limb caused by the deceleration (Mi) b) Calculate the magnitude of force in the patellar tendon (i.e. quadriceps tendon) due to inertia and all other external moments of force =-Trad/s* I-0.41kg m' m=4 ra,-27cm rp-7cm FG 330N rGExplanation / Answer
m = 4 kg
I = 0.41 kg m^2
alpha = -17 rad/s/s
a. inertial moment = I*alpha
L = 0.41*(-17) = -6.97 kg m^2/s^2
b. Fp = ?
net torque on the limb = L
L = Fp*rp + mg*rw - Fg*rg
now, rp = 7 cm
rw = 6 cm
rg = 27 cm
Fg = 330 N
hence
-6.97 = Fp*0.07 + 4*9.81*0.06 - 330*0.27
hence
Fp = 1139.651428 N
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.