Need help writing this program in C++, please explain the fopen function as well, thank you.

yn a program which determines the outer diameter and maximum torque levels of hollow drive shafts. using Cat Engine For this problem, use: 63,000 * HP max = rpm Dread 16* Tmax Shear *(1 - Dratio) Compute Tmax and Dread for the range of HP values: 50 S HP S 100 in steps of 10.0 Definition of terms: HP Horsepower output of the engine rpm Revolutions per minute (use 6000 rpm) Tmax Maximum torque transmitted by the shaft Shear Allowable shear stress of the shaft material (use 11,000 psi) Dratio Ratio of shaft inner diameter to outer diameter (use 0.75) Read the values for rpm, Shear and Diameter ratio from a file fscanf s(). Hint use hard coded values until your computations are correct, ie. Use simple assignment statements, for example rpm =6000. Send your output to a file, and print the file from Notepad (or other editor) case case Engine Drive Shaft Study Motor HP Shaft Torque Motor HP Torque in. lbs Outer Dia Regd. Diameter required (in.) 50 60 70 OWN 525 630 735 840 80 0.708456 0.752847 0.792542 0.828 615 0.861794 0.892599 90 945 100 1050 Hand in