MATLAB PLEASE

paintdata.txt

You are contracted by the Colourblast Paint Company Pty Ltd to test a new product they are developing that produces a very mechanically tough and hard paint finish. Once applied onto a surface, the paint begins to dry and harden, and your job is to use the mechanical indenters in the Department of Materials Science and Engineering at Monash to test the hardness of the setting paint as a function of time to estimate the ultimate, fully cured hardness of their product.

The file paintdata.txt can be found in the question below. It contains two columns of data, the first being time in minutes since application and the second being the measured Vickers hardness in units of HV.

(a) Which of the following models is most appropriate to fit the data give a reason?

i) Exponential model: y = ae^bx

ii) Power model: y = ax^b

iii) Saturation growth model y = ax/(b+x)

iv) Linear model: y = ax + b

(b) What is the ultimate maximum hardness (in units of HV) that the paint surface will achieve when fully cured? Give your answer to at least 1 decimal place.

(c) How long will it take for the paint to reach a hardness of 80% of the maximum attainable hardness (this is the recommended minimum paint setting time)? Give your answer to at least the nearest minute.

Answer

hardness (HV) 14 drying time (min) 65 4 108 7 129 8 173 9 216 10 259 11 302 12 345 12 388 13 431 13 475 14 518 561 15 647 16 777 17 1035 17 1294 18 1553 19 1812 19 2071 19 2588 20 3106 20 3624 20 4141 21 4659 21 5177 21 00 000