Mechanical engineering is one of the broadest engineering disciplines. Mechanical engineers research, design, develop, build, and test mechanical devices, including tools, engines, and machines. Nearly all entry-level mechanical engineering jobs require a bachelor's degree in mechanical engineering. Mechanical engineering degree programs usually include courses in mathematics and life and physical sciences, as well as engineering and design courses. The programs typically last 4 years, but many students take between 4 and 5 years to earn a degree. A mechanical engineering degree program may emphasize internships and co-ops to prepare students for work in industry.