5' 5' F= 100 k W= 80 kl A in in

Structural member AB is to be supported by a strut CD. Determine the smallest length CD may have, and specify where D must be located for a strut of this length to be used. Take x= 120 mm. 60 mm D. y 20 mm E The smallest length CD may have is mm. The coordinates of point Dare ( and Imm.

Modern commercial airliners are largely made of aluminum, a light and strong metal. But the fact that aluminum is cheap enough that airplanes can be made out of it is a bit of historical luck. Before the discovery of the Hall-Héroult process in 1886, aluminum was as rare and expensive as gold. What would happen if airplanes had to be made of steel? The fuselage of the Boeing 747, which can carry 400 passengers, is approximately a hollow aluminum cylinder without ends, 70.7 m long, 6.5 m wide, and 2.5 mm thick (see sketch at right). The fuselage of an airplane Suppose this fuselage was made of steel (density 7.87 g/cm³) instead of aluminum (density 2.70 g/cm³), and let's say the average passenger has a mass of 79 kg. We'll also assume the engines can't lift any greater mass than they already do. Calculate the number of passengers that the Boeing 747 could carry if its fuselage was made of steel. 0 X

A high-carbon steel with a fully pearlitic microstructure was used to form a high-strength bolt (H.-C. Lee et al., J. Mater. Proc. Tech. 211, 1044 (2011)). It was found that the bolt head had an average interlamellar spacing of 257 nm whereas the average spacing in the body of the bolt was 134 nm. Assuming that dislocation pileup is the primary mechanism responsible for the strength of this alloy, what ratio of strength (or hardness) might be expected in the head and body of the bolt?