Thermodynamics

Thermodynamics States About Energy Conversion Thermodynamics is the branch of science that embodies the principles of energy transformation in macroscopic systems. The general restrictions which experience has shown to apply to all such transformations are known as the laws of thermodynamics. These laws are primitive; they cannot be derived from anything more basic. The first law of thermodynamics states that energy is conserved; that, although it can be altered in form and transferred from one place to another, the total quantity remains constant. Thus, the first law of thermodynamics depends on the concept of energy; but, conversely, energy is an essential thermodynamic function because it allows the first law to be formulated. This coupling is characteristic of the primitive concepts of thermodynamics. The words system and surroundings are similarly coupled. A system is taken to be any object, any quantity of matter, any region, and so on, selected for study and set apart (men...

Force and Motion

Forces must be exerted to cut or shape material. These forces are necessary to overcome the resistance offered by the material for instance, in chiseling, sawing, filing and drilling. Forces are also used by the tools and clamping divices. Many production processes are also associated with motion, e.g. turning, milling and drilling.

The unit of forces is the Newton (N). the concept of mass, velocity and acceleration must be understood in order to explain this unit.

Rectilinear motion at constant velocity

It a body travels the same distance in successive time periods of equal duration, it is said to be in uniform motion. This is the sort of motion, for example, of all the feed devices in machine tools.

Example of two instances of motion:
Distance travelled, s1 = 2 m
Time t1 = 10 s

Distance travelled s1 = 2 m
Time t2 = 20 s

The term velocity is used to describe the speed of motion.

The velocity (v) of a body is calculated from the distance (s) travelled by it, in a given period of time (t).

Velocity = distance travelled / time taken ==> v = s/t

Unit of velocity:
The unit of velocity is meter per second (m/s), other unit are kilometer per hour (km/h), meter per minutes (m/min). The example of data that used this speed unit is cutting speed in turning v = 40 m/min, instantaneous velocity of automobile v = 80 km/h, velocity of light v = 300.000 km/sec.

See Also: