Apiece of corroded steel plate was found in a submerged ocean vessel. it was estimated that the original area of the plate was 5 in.2 and that approximately 2.3 kg had corroded away during the submersion. assuming a corrosion penetration rate of 200 mpy for this alloy in seawater, estimate the time of submersion in years. the density of steel is 7.9 g/cm3.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented