interview question

When i am interviewed for a position, i may be asked to describe my reasons for entering a field. i chose mechanical engineer as my major. what is my passions? how do i see my self involved in being a mechanical engineer in the future? whats my philosophy concerning how i intend to make a meaningful contribution in my field (mechanical engineer). 

Target Audience:    Professionals in mechanical engineering

Length:                   2 pages, typed, double-spaced 

Format:                   Times New Roman, 12-point font