To keep the calculations fairly simple, but still reasonable, we shall model a human leg that is 92.0cm long (measured from the hip joint) by assuming that the upper leg and the lower leg (which includes the foot) have equal lengths and that each of them is uniform. For a 70.0kg person, the mass of the upper leg would be 8.60kg , while that of the lower leg (including the foot) would be 5.30kg .
Find the -coordinate of the center of mass of this leg, relative to the hip joint, if it is stretched out horizontally.
xcm= (maxa +mbxb)/(ma+ mb)
The Attempt at a Solution
xcm= ((8.6*23) + (5.3*69))/ (13.9)=40.5cm
However, this has come back as incorrect. Where do I go from here?