Mechanical Engineering is one of the most important branches of engineering. Mechanical Engineers apply the principles of mechanics and energy to the design of machines and devices. Hence, they must be able to control mechanical systems and usually work with other professionals in designing these systems. Automobiles, engines, heating and air-conditioning system, gas and steam turbines, air and space vehicles, trains, ships, servomechanisms, transmission mechanisms, machine tools, material handling systems, elevators and escalators, and robots used in industry are a few of the systems and devices requiring mechanical engineering knowledge.