17.28 For each of the metals listed in the following + table, compute the Pilling-Bedworth ratio. Also, on the basis of this value, specify whether you would expect the oxide scale that forms on the surface to be protective, and then justify your decision. Density data for both the metal and its oxide are also tabulated. Metal Density (g/cm) Oxide Density (g/cm) Metal Metal Oxide Mg 1.74 MgO 3.58 V 6.11 3.36 Zn 7.13 ZnO 5.61

The figure below shows the essential parts of a hydraulic brake system. The area of the piston in the master cylinder is 1.8 cm² and that of the piston in the brake cylinder is 6.4 cm2. The coefficient of friction between shoe and wheel drum is 0.50. If the wheel has a radius of 37 cm, determine the frictional torque about the axle when a force of 50 N is exerted on the brake pedal. N. m Wheel drum Pedal Shoe Master cylinder cylinder Brake

At what temperature does solidification form at 10% Ni? T(°C) 1600 1500 1400 1300 1200 1100 1000, Answer: L (liquid) L+a solidus liquidus 20 40 60 wt% Ni 86 100

A scientist has three unlabeled samples of pure metals. He wants to determine the identity of each metal.