ABSTRACT. Most materials expand when their temperature increase and shrink when their temperature decrease. These are the caused by thermal expansion. There are different factors affecting the change in length in thermal expansion. The change in length is found to be proportional to the change in temperature. It also depends on the initial length of the rod. Different materials have different coefficient of linear expansion which means that the kind of material also affects the change in length in thermal expansion.

INTRODUCTION
All materials, solid, liquid or gas experience a change in its dimension whenever there is a change in its temperature. With the exception of water which expands anomalously at a temperature below and above 20°C, materials in general expand when the temperature rises and shrinks as the temperature decreases. The change in dimension could be one dimensional called the linear expansion, it may be two dimensional which is expansion of the area, or three dimensional which known as volume expansion. The change in the body’s dimension is a function of the temperature. The amount of expansion also depends on the initial state and the dimension of the body. It was observed also that gas experiences a considerable change in dimension, followed by liquid, and the least is that of solid. This may be due to the difference in the molecular structure of the material when it is in different state.

It was found out that for change in temperature less than 100 C°, the electrical resistance of a metal is proportional to the temperature. This concept shall be used to determine the temperature. This concept shall be used to determine the temperature of the body if the electrical resistance is known.

Theory
Consider a rod of initial length L0 a...

-2 /wiki/thermal_expansion 0.0000328 000 1 1.25 100 110 12 12th 17.8 2 20 2008 23 3 3000 37.96 77 800 abl abstract accomplish accumul achiev acknowledg actual affect air allow alreadi also aluminum alway amount ampl anomal anoth apparatus appli applic area assur atm base best big bodi boil bolt built built-in bush c calibr call cast caus celsius chain chang coeffici combin compar comput concept conclus condit condition consid consider constant contract convert cool cooper copper correspond could data de dear decreas defin definit degre depend design determin dial diamet diamond differ difficulti dimens dimension direct discuss distanc done due e.g edit electr en.wikipedia.org en.wikipedia.org/wiki/thermal_expansion engin eqn equat error essenti even everi everyth except expand expans expect experi experiment explain express fact factor famili faster figur final finish first fit flexibl foam follow ford forget found freedman fun function gas gather gaug general generat give given god graphit greater group groupmat guidanc h hardship heat hot hotter idea increas initi inner inspir insul introduct invers keep kind know known l l-l0 l0 l0α laboratori land larg last learn least length leon less lf lightn like linear liquid ll0 lot low main make mass materi may mean measur mechan member mention mentor metal meter methodolog miss mm modern molecular motiv mould move multi multi-test must necessari need normal object observ offer ohm one origin owe part percentag perfect physic place pp prepar pressur prof professor proport provid push put quot r ratio reach read real recogn refer relat relationship resist rest result retriev ricardo right rise rod room rubber sacrific say school second see sensit set shaft shall shot show shown shrink sinc slight slightest smaller solid solv sourc state steam stick structur studi success suffici sun support survey t0 tabl take tape temperatur tester tf thank theori therefor thermal thermistor thick thin thing three thus time touch troubl tube two univers us use valu vital volum want water week whatev whenev wisdom without would wouldn wrong young zero α