The calculator was demonstrated for us in class once, and I also used it personally.
The quality of content:
It was very helpful in relating the effect of different input to the output. It helped me to pick up on the relations of the properties. By using different input and raising and lowering them, I was able to relate them more easily and understand that, e.g. "if I take this pressure ratio up, the mach numbers get closer together."
The potential effectiveness for enhancing teaching and learning:
I think it was very helpful when used in the classroom, and can be utilized that way in almost any class working with aerodynamics.
The ease of using the materials:
This was the only problem I had with the applet. Though inputting numbers was easy, I felt the output could have been better labeled so that it was easier to figure out what all of the numbers and ratios referred to. As someone who isn't real familiar with aerodynamics, and had only used the application once in class before I tested it myself, initially I couldn't remember what it all stood for.