Chapter 18, Problem 25ICA

A phase diagram for carbon and platinum is shown. It is assumed the lines shown are linear, and the mixture has the following characteristics. The endpoints of the division line between these two phases are labeled on the diagram.

■    Below 1700 degrees Celsius, it is a mixture of solid platinum (Pt) and graphite (G).

■    Above 1700 degrees Celsius, there are two possible phases: a Liquid (L) phase and a Liquid (L) + phase (G).

Write a program to determine the phase. The program should ask the user to enter the weight percent carbon and the temperature in degrees Celsius. Call the phases “Pt + G,” “L,” and “L + G,” for simplicity. If the point falls directly on the T = 1700°C line, include the point in the “Pt + G” phase. If the point falls directly on the L, L + Gline, include the point in the “L + G” phase.

Store the phase as text in a variable. The equation of the line dividing the L and L + G phases must be found in the program using polyfit. The program should produce a formatted output statement to the command window. Similar to “For X.XX weight percent carbon and a temperature of YYY degrees Celsius, the phase is PHASE” where x.xx, yyy and PHASE are replaced by the actual values formatted as shown.

The following partial code is designed to implement this program. You are to fill in the missing sections of code as appropriate to complete the program.