EXPANSION

Science Words

HeatTo expandTo contractLinear expansion coefficient Volume expansion coefficient

Objectives

To do an expansion experiment on solid, liquid, and gas.To explain the advantages of expansion in the daily life.

The steel on the track of the train at night/cool (left) and at noon/hot (right).

Steel on the bridge should be set apart to overcome the iron expansion and contraction .

The track of the train bends .

The road damage

PROBLEMWhat's happenwhen the matter heated

Do you remember About Theory Kinetic matter

The matter will expandWhy.Please explain using theory kinetic matter

conclusionAppropriate Theory kinetic matterThe matter expansion if heated because Moving particles fasterdistance between particles with the other be longer

MUSSCHENBROEK

Investigating Solid Expansion

Apparatus and Materials- Musschenbroek set and Bunsen burner-Three different kinds of different metal bar

Procedures1. Take a metal bar and put it on Musschenbroek apparatus as seen in the figure.2. Turn the spanner in the Musschenbroek apparatus so that the indicator arms are in the same position3. Heat the metal bar evenly by using the Bunsen burner. Observe carefully those indicator arms that are pushed by the metal bar. Repeat your experiment for the other two metal bars.

AnalysisWhat do you observe on those indicator arms? Do they move? In your opinion, is there any relation between the movement of those indicator arms and the kinds of metals that push them?

Kinds of metals with its linier expansion coefficient

Glass 9.10-6 / o CPyrex Glass 4.10-6 / o CAluminum24.10-6 / o CBrass19.10-6 / o CSteel13.10-6 / o CCopper17.10-6 / o C

The materials or the kinds of solids influence the solid expansion.

The Linear Expansion Coefficient () is a value that states the rate of an expansion speed of an object per temperature degree.

The higher linear coefficient of an object is, the faster the object will expand. Solid expansion is useful for our daily life.

Bimetal strip consists of two metals of different expansion coefficient (brass and steel).

Properties of bimetalThe bimetal heated will bend to direct metal which have smaller linier expansion coefficientThe bimetal cooled will bend to direct metal which have greather linier expansion coefficient

Thermostat.T-Bimetal thermometer.

The linear expansion which occurs on a metal bar .

where l = the difference of length of an object before (lo) and after expansion (l1); = the linear expansion coefficient of material; = the initial length of an abject; T = the difference of temperature before and after expansion.

Example

A train track which is made of steel has the length of 40 meters on 0 oC. How long is its expansion if it is heated until 100 oC?

Known linitial = 40 metersT = 100 oC - 0 oC = 100 Costeel = 0.000011/Co

Question: l = ?Equation:

Solution: l = (0.000011/Co) (40 meter) (100 Co) = 0.044 meter

ExcercisesA copper bar at 10 oC is 10 meter long, then it is heated up to 20 oC. Determine the length expansion of that copper bar during the heating process if its expansion coefficient is 0.000017/Co.

A Pyrex glass with initial length of 2 meters is heated up to 30 oC from initial temperature. Determine the length expansion of that glass if its length expansion coefficient is 0.00003/Co.

exercisesLength of the copper bar at 30oC is 20 m, then it heated up to 80oC. Determine length of the copper bar now if linier expansion coefficient copper bar is 0.000017/oC

EXPANSION IN GASOpening bottle caps easily

Investigating Gas Expansion

Apparatus and MaterialsWater, candle, and beaker glassBoiling flask, rubber cork, and capillary pipe.

ProceduresPut the rubber cork on boiling flash and then put the capillary pipe into rubber cork's hole.Fill the beaker glass with sufficient water, and plunge the open edge of the capillary pipe into the water. Observe the surface of the water in capillary pipe.Heat the boiling flask with a candle. Observe what happens to the surface of the water in that beaker glass.

Analysis

Based on the result of the experiment and your observation, how is the shape of the water surface in the capillary pipe? What happens to the water in the beaker glass after the boiling flask is heated? In your opinion, how does it happen?