For liquids, the dynamic viscosity , which is a measure of resistance against flow is approximated as

For liquids, the dynamic viscosity μ, which is a measure of resistance against flow is approximated as μ = a10^b/(T–c), where T is the absolute temperature, and a, b and c are experimental constants. Using the data listed in Table A-7 for methanol at 20ºC, 40ºC and 60ºC, determine the constant a, b and c.

Table A-7

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TABLE A-7 Properties of liquids Specific Heat Cp p, kg/m³ J/kg-K Temp. Density T, °C -160 420.2 -150 405.0 -140 388.8 -130 371.1 3492 3580 3700 3875 -120 351.4 4146 -110 328.8 -100 301.0 -90 261.7 20 30 40 50 50 70 788.4 2515 2577 769.6 2644 2718 2798 2885 779.1 760.1 60 750.4 740.4 -100 683.8 -75 659.3 -50 634.3 -25 608.2 0 580.6 25 550.7 4611 5578 8902 50 517.3 75 478.5 100 429.6 1881 1970 2069 2180 2306 2455 2640 2896 3361 Thermal Conductivity k, W/m-K 0.1863 0.1703 0.1550 0.1402 0.1258 0.1115 0.0967 0.0797 0.1987 0.1980 0.1972 0.1965 0.1957 0.1950 0.1383 0.1357 0.1283 0.1181 0.1068 0.0956 0.0851 0.0757 0.0669 Thermal Diffusivity a, m²/s Methane (CH₂) 1.270 x 107 1.174 x 10-7 1.077 x 10-7 9.749 x 10 B 8.634 x 10-8 7.356 x 108 5.761 x 10-8 3.423 x 10-8 1.002 x 10-7 9.862 x 10 # 9.690 x 108 9.509 x 10 8 9.320 x 108 9.128 x 10-8 Methanol [CH₂(OH)] Dynamic Viscosity μ, kg/m-s 1.075 x 10 7 1.044 x 107 9.773 x 10 8 8.906 x 10 B 7.974 x 108 1.133 x 10-4 9.169 x 10- 7.551 x 10-5 6.288 x 10-D 5.257 x 10 5 4.377 x 10-5 3.577 x 10-5 2.761 x 10-5 Isobutane (R600a) 7.069 x 10 8 6.233 x 5.460 x 10-8 108 10 8 4.634 x 5.857 x 10-4 5.088 x 10-4 4.460 x 10 4 3.942 x 10-4 3.510 x 10-4 3.146 x 10 4 9.305 x 104 5.624 x 10-4 3.769 x 10-4 2.688 x 10-4 1.993 x 10-4 1.510 x 10 4 1.155 x 10-4 8.785 x 10-5 105 6.483 x Kinematic Viscosity », m²/s 2.699 x 10-7 2.264 x 10-7 1.942 x 10-7 1.694 x 10-7 1.496 x 10-7 1.331 x 10-7 1.188 x 10-7 1.055 x 10-7 7.429 x 10-7 6.531 x 107 5.795 x 10-7 5.185 x 10-7 4.677 x 10-7 4.250 x 10-7 1.360 x 10-6 8.531 x 10-7 5.942 x 107 4.420 x 107 3.432 x 107 2.743 x 10-7 2.233 x 10-7 1.836 x 107 1.509 x 10-7 Prandtl Number Pr 2.126 0.00352 1.927 0.00391 1.803 0.00444 1.738 0.00520 1.732 0.00637 1.810 0.00841 2.063 0.01282 3.082 0.02922 7.414 6.622 5.980 5.453 5.018 4.655 Volume Expansion Coeff. B. 1/K 12.65 0.00118 0.00120 0.00123 0.00127 0.00132 0.00137 0.00142 8.167 0.00150 6.079 0.00161 4.963 0.00177 4.304 0.00199 3.880 0.00232 3.582 0.00286 3.363 0.00385 3.256 0.00628