Question

Chapter 8 Part 2: 8.45

To keep the calculations fairly simple, but still reasonable, we shall model a human leg that is 92.0 cm 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 70.0 kg person, the mass of the upper leg is 8.35 kg , while that of the lower leg (including the foot) is 5.50 kg . Take the x-axis to be directed horizontally and the y-axisto be directed vertically downward.

Part A)

Find the y-coordinate of the center of mass of this leg, relative to the hip joint, if it is fully extended along the y axis.

Express your answer to three significant figures.

Part B)

Find the x-coordinate of the center of mass of this leg, relative to the hip joint, if it is fully extended.

Express your answer to the nearest integer.

Part C)

Find the x-coordinate of the center of mass of this leg, relative to the hip joint, if it is bent at the knee to form a right angle with the upper leg (which is parallel to the ground).

Express your answer to three significant figures.

Part D)

Find the y-coordinate of the center of mass of this leg, relative to the hip joint, if it is bent at the knee to form a right angle with the upper leg (which is parallel to the ground).

Express your answer to three significant figures.