There are a total of six elective slots. Of these six, one must be a mechanical engineering technical elective; four can be any course in the university except for a physical education or ROTC course; and one can be any course offered by the university.

A list of the acceptable courses is given under the heading Technical Elective Courses in the mechanical engineering section of the Undergraduate Catalog. These courses must be electives offered by the mechanical engineering department and must have a course number of 24-XXX.

Certain instruction-based mechanical engineering graduate courses can also be used to satisfy this requirement, provided that you have met the prerequisites and have obtained the approval of the instructor.

If a course is not listed under the heading Technical Elective Courses in the mechanical engineering section of the Undergraduate Catalog, then it does not satisfy this requirement. 

In particular, the courses 24-391/392 Mechanical Engineering Project, 24-491/492 Departmental Research Honors, and 24-201 Engineering Graphics cannot be used to satisfy the mechanical engineering technical elective requirement.

No. The intent behind the technical elective requirement is to increase your exposure to mechanical engineering and obtain depth in certain elective areas. Courses from outside the department, even if taught by a mechanical engineering faculty member, do not normally satisfy the technical elective requirement. Of course, 39-XXX courses can be used to fill your five other elective slots.