The yield strength for fe that has an average grain diameter of 1 x 10-2 mm is 230 mpa. at a grain diameter of 6 x 10-3 mm, the yield strength increases to 275 mpa. at what grain diameter will the yield strength be 310 mpa? (b) a specimen of steel with kic = 54.8 mpa-m1/2 and ys = 1400 mpa is loaded in tension. if this specimen has an internal crack, 2a = 0.4 mm, will it fail after plastic deformation or by brittle fracture? assume y=1.0.

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?

One number is said to be an "order of magnitude" larger than another number if choose one: a. it is 10 times larger. b. it is 5 times larger. c. it is 3 times larger. d. it is 100 times larger. e. it is 2 times larger.

Does heating a metal wire increase or decrease its electrical resistance? why?