The Main-Sequence: The star now settles down to a long period of stability while the hydrogen at its centre is converted into helium with the release of an enormous amount of energy. This stage is called the main-sequence stage, a reference to the classical Hertsprung-Russell diagram (see the Figure below). Most stars lie in a well defined band in the diagram, and the only parameter that determines where in the band they lie is the star's mass.
Becoming a Professional Engineer (PE) A Professional Engineer (PE) is an engineer certified by a state board of registration to practice engineering. The PE license is the engineering profession's highest standard of competence, a symbol of achievement and assurance of quality. The College of Engineering believes that professional registration is an important goal for engineering graduates. Passing the FE Exam is the first step toward that goal.
Examples of constraints could include the materials, cost, or time to design the device. Assessment Boundary: Devices should be limited to those that convert motion energy to electric energy or use stored energy to cause motion or produce light or sound. A Peformance Expectation (PE) is what a student should be able to do to show mastery of a concept. Some PEs include a Clarification Statement and/or an Assessment Boundary. These can be found by clicking the PE for More Info..