The kinetics of some phase transformations obey the avrami relationship. using the fraction transformed-time data given below, determine the total time required for the transformation to go to 91% completion.

fraction transformed time (s)

0.3 11.8

0.8 26.0

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.