4. The figure shows a riveted lap joint with cover plates connecting two steel plates. Each rivet has diameter of 12 mm and the thickness of each steel plate is 15 mm. (a) Compute the shear stress (MPa) in each rivet due to a force of 10.2 kN applied to the plates. (b) If the bearing stress in the steel plates is limited to 40 MPa, what is the allowable load P (kN)? (c) If the width of the steel plates is 100 mm what is the allowable load P (kN) for a limited normal stress of 20 MPa? rivet cover plate Steel plate cover plate

A firefighter weighs 730 N. She wears shoes that each cover an area of 309cm2. (a) What is the average stress she applies to the ground on which she is standing? (b) How does the stress change if she stands on only one foot? Show working equations for both (a) and (b). Answer must be in kPa.

Between each pair of vertebrae in the spinal column is a cylindrical disc of cartilage. Suppose that such a particular disc of cartilage has a a radius of 3.118 cm (100cm = 1 meter) and a thickness of 6.877 mm (1000mm= 1meter).  The shear modulus of cartilage is 1.2 × 107 N/m2. Suppose that a shearing force of magnitude 9 N is applied parallel to the top surface of the disc while the bottom surface remains fixed in place. How far does the top surface move relative to the bottom surface in microns (1 meter = 106 microns)?

Two wooden members, each having a width of b = 2.4 in. and a depth of d = 0.8 in., are joined by a simple glued scarf joint. Assume B = 47°. If the allowable shear stress for the glue used in the joint is 94 psi, what is the largest axial load P that may be applied? Answer: P = i ! Ib