1. A man with a mass of 72.9 kg stands on one foot. His femur has a cross-sectional area of 8.00 cm² and an uncompressed length 49.8 cm.Young's modulus for compression of the human femur is 9.40 10⁹ N/m².

What is the fractional length change of the femur when the person moves from standing on two feet to standing on one foot?

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2. Two steel plates are fastened together using four bolts. The bolts each have a shear modulus of 80.0 GPa and a shear strength of 606 MPa. The radius of each bolt is 0.810cm. Normally, the bolts clamp the two plates together and the frictional forces between the plates keep them from sliding. If the bolts are loose, then the frictional forces are small and the bolts themselves would be subject to a large shear stress. What is the maximum shearing forceFon the plates that the four bolts can withstand?