A thin film of radioactive copper was electroplated on the end of a copper cylinder. After a high temperature anneal of 20 hours, the specimen was sectioned and the following profile of the radioactive copper was obtained. distance (cm) concentration (atom fraction)
0.005 0.168
0.01 0.157
0.02 0.119
0.03 0.075
0.04 0.039
0.05 0.017
0.06 0.006
(a) Determine the tracer ( ∗ iD ) and self (Di) diffusion coefficient of copper.
(b) Using ∗ iD , plot the concentration profile of electroplated radioactive copper after high temperature anneal of 40 hours.

Aplate clutch has a single pair of mating friction surfaces 250-mm od by 175-mm id. the mean value of the coefficient of friction is 0.30, and the actuating force is 4 kn. a) find the maximum pressure and the torque capacity using the uniform-wear model. b) find the maximum pressure and the torque capacity using the uniform-pressure model.

Draw the engineering stress-strain curve for (a) bcc; (b) fcc metals and mark important points.

Afoot bridge is made as a simple deck, 4 m long, with a cross section 2 m (wide) and 20 cm thick, and made of wood. the deck is supported at the two ends. the maximum load allowable on the bridge is 10 tons, provided it is uniformly distributed on the deck. to sense this load, a strain gauge is placed at the center of the bridge and its resistance is monitored. if the sensor has a nominal resistance of 350 s2 and a gauge factor of 3.6, what is the reading of the strain gauge at maximum load? the modulus of elasticity for the wood used in the construction is 10 gpa.