Assume that a specific hard disk drive has an average access time of 16ms (i. e. the seek and rotational delay sums to 16ms) and a throughput or transfer rate of 185MBytes/s, where a megabyte is measured as 1024.

Required:
What is the average access time for a hard disk spinning at 360 revolutions per second with a seek time of 10 milliseconds?

Along steel shaft of 10 cm diameter is austenised at 870°c and then quenched in a liquid at 30oc. the average surface heat transfer coefficient is 2000 w/m2. °c. the relevant thermophysical properties of the shaft are: p=7800 kg/m", k=20 w/mk, cp=0.46 kj/kg.k calculate: a)-the time required for the center temperature to drop to 200°c. b)-the temperature at half-radius at that moment. c)-the amount of heat that had been transferred to the liquid by that time per meter length of the shaft