HOW FAST SOUND TRAVEL IN WATER?

MEMBER:

TERRENCE ONG JUN HAN

TAY WEI KIAN

CHAI MINNG HAO

TEACHER:

PN. NORATIQAH BINTI MOHD AMIN

ABSTRACT

• SOUND PRESSURE IS A VIBRATION THAT PROPAGATES AS A TYPICALLY AUDIBLE MECHANICAL WAVE OF PRESSURE THROUGH MEDIUM SUCH AS WATER AND AIR.

• SOUND CAN BE PROPAGATE THROUGH SEVERAL MEDIUM AND PRODUCES

A) LONGITUDINAL WAVE

B) TRANSVERSE WAVE

• AS THE SOUND WAVE IS CONTINUOUSLY PRODUCED BY THE SOURCE, AT ANY FIXED DISTANCES, THE PRESSURE, VELOCITY, AND DISPLACEMENT OF THE MEDIUM VARY IN TIME

• THEREFORE, DURING ANY PROPAGATION, WAVES CAN BE REFLECTED, REFRACTED OR ATTENUATED BY THE MEDIUM.

INTRODUCTION

• ECHO SOUNDING IS A TYPE OF SONAR USED TO DETERMINE THE DEPTH OF WATER BY TRANSMITTING SOUND PULSES INTO WATER. THE TIME INTERVAL BETWEEN EMISSION AND RETURN OF A PULSE IS RECORDED, WHICH IS USED TO DETERMINE THE DEPTH OF WATER ALONG WITH THE SPEED OF SOUND IN WATER AT THE TIME. THE WORD SOUNDING IS USED FOR ALL TYPES OF DEPTH MEASUREMENTS. ECHO SOUNDING IS A MORE RAPID METHOD OF MEASURING DEPTH THAN THE PREVIOUS TECHNIQUE OF LOWERING A SOUNDING LINE UNTIL IT TOUCHED BOTTOM.

• DISTANCE CAN BE MEASURED BY MULTIPLYING HALF THE TIME FROM THE SIGNAL'S OUTGOING PULSE TO ITS RETURN BY THE SPEED OF SOUND IN THE WATER, WHICH IS APPROXIMATELY 1.5 KILOMETRES PER SECOND [T÷2×(4700 FEET PER SECOND OR 1.5 KIL PER SECOND )]

• FOR HIGH ACCURACY DEPTHS, USUALLY RESTRICTED TO SPECIAL PURPOSE OR SCIENTIFIC SURVEYS, A SENSOR MAY BE LOWERED TO MEASURE THE TEMPERATURE, PRESSURE AND SALINITY. THESE FACTORS ARE USED TO CALCULATE THE ACTUAL SOUND SPEED IN THE LOCAL WATER COLUMN. THIS LATTER TECHNIQUE IS REGULARLY USED BY US OFFICE OF COAST SURVEY FOR NAVIGATIONAL SURVEYS OF US COASTAL WATERS.

LITERATURE REVIEW• THROUGH THE USAGE OF WAVE, ‘ECHO LOCATE’ IS USED TO LOCATE ANY

OBSTRUCTION WHICH IS USUALLY USED IN SUBMARINE FOR UNDERWATER NAVIGATION OR BAT DURING AERIAL NAVIGATION.

• ‘ECHO SOUNDER’ IS ALSO DISCOVERED THROUGH THE USAGE OF WAVE TO MEASURE THE DEPTH OF WATER. ,MODERN DEVICES IS ABLE TO USE THIS PROCESS BY SENDING PULSE AND CALCULATE THE TIME TAKEN TO RECEIVE BACK THE ECHO. BY THIS, THEY ARE ABLE TO MEASURE THE MOST PROBABLE DEPTH IN THE OCEAN.

• OBJECTIVE• • TO DETERMINE DOES SOUND WAVE CAN TRAVEL IN WATER.

• • TO DETERMINE THE RELATIONSHIP BETWEEN VOLUME OF WATER IN CONTAINER AND THE TIME TAKEN FOR SOUND WAVE TRAVEL TO SURFACE OF THE WATER.

• • TO DETERMINE HOW DOES THE WATER VOLUME AFFECT THE TIME TAKEN OF SOUND WAVE TRAVEL TO SURFACE OF THE WATER.

• PROBLEM STATEMENT• SOUND IS A TYPE OF WAVE THAT TRAVEL IN A MEDIUM. FOR THIS EXPERIMENT, WE HAVE TO

DETERMINE DOES THE WATER TRAVEL IN A WATER MEDIUM AFFACT THE SPEED OF THE SOUND WAVE TRAVEL AND AFFACT THE TIME TAKEN TO APPROACHING THE SURFACE OF THE WATER?

• HYPOTHESIS• SOUND TRAVEL DIFFERENT SPEED IN DIFFERENT MEDIUM. WHEN THE WATER PRESSURE

INCREASE, THE SPEED OF SOUND TRAVEL DECREASE.

•METHODOLOGY

• MATERIALS AND APPARATUS:• 1. 1MHZ AUDIO GENERATOR• 2. TWO CROCODILE CLIP WIRES• 3. SPEAKER• 4. BEAKER• 5. MEASURING CYLINDER• 6. IRON CONTAINER• 7. STOPWATCH• 8. WATER

• PROCEDURE:• 1. SETUP THE APPARATUS AS THE PHOTO SHOWN. • 2. PLACE THE IRON CONTAINER ON THE SPEAKER.• 3. SET THE 1MHZ AUDIO GENERATOR TO 250HZ TOGETHER WITH HIGHEST AMPLITUDE.• 4. FILL 50ML OF WATER INTO A IRON CONTAINER BY USING MEASURING CYLINDER.• 5. START THE STOPWATCH WHEN THE AUDIO GENERATOR IS SWITCHED ON.• 6. TIME TAKEN IS RECORDED WHEN A PATTERN OF WAVE IS APPEARED ON WATER SURFACE.• 7. REPEAT STEP 2 TO 6 UNTIL TOTAL VOLUME OF WATER IS 250ML, RECORD ALL THE READINGS AND

TABULATE VOLUME OF WATER (V/ML) AND TIME TAKEN WAVE PATTERN TO FORM (T/S)• 8. PLOT A GRAPH OF T AGAINST V.

RESULTVolume of water, (ml) (+-0.1ml)

Time taken for wave to form on the surface of water (s) (0.1)

(+- 0.01s)

  1 2 3 4 5 Average

50 0.75 0.94 0.84 0.78 1.10 0.882

100 1.47 0.81 1.03 1.22 1.00 1.106

150 1.50 1.78 1.81 1.94 2.19 1.844

200 2.69 2.78 3.16 2.66 2.47 2.752

250 5.28 5.75 3.19 3.75 4.22 4.582

•DISCUSSION:• 1. THE FREQUENCY OF THE SPEAKER IS MAINTAINED AT AROUND 250 HZ TO MAINTAIN

CONSISTENCY OF THE READING.

• 2. THE EYE IS PLACED AT MENISCUS LEVEL SO THAT ANY WAVE FORMED CAN BE EASILY OBSERVED.

• 3. THE EXPERIMENT IS REPEATED FOR FIVE TIMES TO GET THE ACCURATE READING.

• 4. FAN OF THE LAB IS SWITCHED OFF TO ENSURE NO EXTERNAL FORCE APPLIED ON WATER SURFACE.

• 5. ON THE GRAPH, WHEN THE VOLUME IS 0ML, THERE IS STILL A TIME TAKEN FOR SOUND TRAVEL TO THE SURFACE DUE TO THE IRON CONTAINER IS ALSO A MEDIUM.

•CONCLUSION:• THE HIGHER THE VOLUME OF WATER IN THE METAL PLATE, THE LONGER THE

TIME FOR THE WAVE TO FORM ON THE SURFACE OF WATER.

APPENDIX

REFERENCES

• HTTP://EN.WIKIPEDIA.ORG/WIKI/SONAR

• HTTP://EN.WIKIPEDIA.ORG/WIKI/ECHO_SOUNDING

• HTTP://EN.WIKIPEDIA.ORG/WIKI/SOUND

• OXFORD FAJAR ACE AHEAD STPM TEXT PHYSICS THIRD TERM

• PRE-U TEXT STPM PHYSICS

• PHYSICS FOR SCIENTISTS & ENGINEERS – DOUGLAS C.GIANCOLI