### Thermodynamic System

The thermodynamic system may be defined as a definite area or a space where some thermodynamic process takes place. It may be noted that a thermodynamic system has its boundaries, and anything outside the boundaries is called its surroundings. The thermodynamic system may be classified into the following three groups :

1. Closed system. This is a system of fixed mass whose boundaries are determined by the space of the working substance occupied in it. In a closed system, heat and work cross the boundary of the system, but there is no addition or loss of the original mass of the working substance. Thus the mass of the working substance which comprises the system, is fixed.

2. Open system. In this system, the working substance crosses the boundary of the system. The heat and work may also cross the boundary.

3. Isolated system. It is a system of fixed mass and no heat or work cross its boundary.

### Are Engineers Favourite Among Girls?

What do girls think about men who are engineers and what type of engineers are most favourite among girls? A survey was conducted by a team of aboutmech with members chosen from different countries. Each team member carried out a neutral survey in his/ her country to evaluate what females think about most of the engineers from different engineering branches. An overview of different questions asked in survey is given below: Question: Which male engineers do you find more attractive as a husband? Almost 50% women voted for mechanical engineers to be the most attractive husbands among other engineers. So mechanical engineers are most favourite among girls as a husband. They find them more trustworthy, intelligent, and creative. A married women from California said, “If your husband is a mechanical engineer, he will help you in everyday tasks. Because mechanical engineers are good team players and they have creative ideas about everything.” Which male engineers do you find more

### Engineering Mechanics - Introduction

The Engineering Mechanics is that branch of Engineering-science which deals with the principles of mechanics along with their applications to engineering problems. It is sub-divided into the following two main groups: (a) Statics, and (b) Dynamics The Statics is that branch of Engineering Mechanics which deals with the forces and their effects, while acting upon the bodies at rest. The Dynamics is that branch of Engineering Mechanics which deals with the forces and their effects, while acting upon the bodies in motion. It is further sub-divided into the following two branches: (i) Kinetics, and (ii) Kinematics The Kinetics is that branch of Dynamics, which deals with the bodies in motion due to the application of forces. The Kinematics is that branch of Dynamics which deals with the bodies in motion without taking into account the forces which are responsible for the motion.