Experiment on Testing The Effects of Vibrations In Different

Weight of Object and Length of String

CikaL – Amri Secondary School

MYP Year 8

Science Project

By:

Salsabil Inas Labiba

Jakarta, Indonesia

2012

Content

Preface______________________________________________________________3

CHAPTER I

Purpose_____________________________________________________________4

Introduction__________________________________________________________4

CHAPTER II

Hypothesis___________________________________________________________5

Materials and Methods_________________________________________________5

CHAPTER III

Data________________________________________________________________6

Result_______________________________________________________________7

Conclusion___________________________________________________________7

Work Cited__________________________________________________________9

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Preface

Firstly, I would like to say thank you to Allah SWT to let me start and finish

this experiment well, also finish this report after doing the successful experiment to

prove out the vibration throughout in terms of physics. Secondly, I would like to say

thank you to Miss Dewi Pramesti Kusumaningrum as my science teacher who picked

this topic, ‘Vibration and Wave’ from physics that I have never know before. Also,

she helps me on understanding the topic well by doing several exercises that train my

brain to be more understand. And at the end, she helps me while doing this

experiment that understand me more about vibrations and waves by using simple

materials, which are a piece of string, metals, ruler, and a stopwatch.

Also, I would like to say thank you to my group mates, Agalia Sakanti

Ardyasa, Azzah Al Zahra Farras, and Hapsari Athaya Mulyanissa who helped me a

lot while dong this experiment because without them, I cannot finish it all by myself

because it needs different person to count the vibrations and hold the stopwatch, also

taking pictures.

As we all know, each experiment always ends up with its own result also its

own relevant reason that teaches the person the other lesson that might people do not

know because the speed of the string and the air condition since it could affect the

string’s speed would not be the same with the other group.

By doing this experiment, we could be more proficient about vibration and

wave that included into physics knowledge that is a new learning for us. This could

open our curiosity about science life.

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CHAPTER I

Purpose

In this term, we are learning about ‘Vibrations and Wave’ in terms of physics

since vibrations and wave have been the highlight in this techno world and becomes

its important material in technology industries by helping the technology

development.

By that, we want to examine the vibration result with two different variables,

by changing its weigh and its amplitude length and how much the effects that happen

along. We are using 2 different sections, with using 2 metals and 4 metals as its

weigh. Each of the weigh would be examine on different length, so there would be 4

experiments.

Introduction

Vibration is the mechanical oscillation of an object, which passes its balance

position that has its frequency by counting the number of vibrations, produced in

particular time, so it measures the vibrations produced in one second. It has its

furthest distance that called as amplitude. We also can count the time needed to make

one vibration, and it is called as its period.

If we are wanting to find its example, it might be not that difficult because the

way we see is one of the vibration example, which is visible light that is included into

electromagnetic waves around us. Besides seeing, we also could see the example from

the vibration that the seismograph captured while there is an earthquake and water

ripples when we throw a stone into a pond or lake.

Meanwhile, we want to know the effects of the vibration results if the string

affected by the weigh of the object and the length of the string.

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CHAPTER II

Hypothesis

Since we are using different kind of weigh, which are 2 metals weigh and 4

metals, the lightest weight would produce the more vibrations since it has less

pressure to bring. Besides the weigh is changed, the length of the string is also

changed. The longest string would produce the more vibration since it brings the more

power to bring the metal.

Materials and Methods

Materials:

- A piece of string as a hold for the metals

- Metal rings: 4 pieces to differentiate the weigh

- Ruler to measure the amplitude

- Stopwatch to count the time spent

- Tape to hold the string

Method:

- Tied the metals perfectly, make sure it wont fly off when you swing it

- Tape the string’s end that is not tied to the metals, to the table. Make sure it

wont fall off

- Measure the amplitude by measuring the string

- Start to swing the string along as pressing the stopwatch to start the time

This experiment is testing how much vibrations produced in different weigh and

different length of string. It will be tested until the vibrations end.

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CHAPTER III

Data

Experiment with 2 metals:

WITH 2 METALS Vibrations Time Frequency Period

25 cm

(Amplitude: 25 cm)

528 vibrations 4:03 minutes 2.172 Hz 0.460 sec

40 cm

(Amplitude: 40 cm)

464 vibrations 3:46 minutes 2.053 Hz 0.487 sec

Experiment with 4 metals:

WITH 4 METALS Vibrations Time Frequency Period

25 cm

(Amplitude: 23 cm)

490 vibrations 3:00 minutes 2.72 Hz 0.367 sec

40 cm

(Amplitude: 43 cm)

477 vibrations 4:09 minutes 1.915 Hz 0.522 sec

25 cm 40 cm450

460

470

480

490

500

510

520

530

540

550

2 Metals4 Metals

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Result

After doing the experiment, we could know that the more long string would

be, the less vibrations that it produces. Also, the less mass that it brings produces the

vibrations from the string. Even though if we see the table, the time that it took is not

in a perfect pattern, but at the end, the amount of the vibrations and the period is

telling the same reason that the lighter mass and the shorter length that the pendulum

has, the more vibrations that will it produces.

The swing of the pendulum is actually affected by its length that determines

the frequency and period. This is also agreed by Galileo Galilei that pendulum has a

constant period even when moving in different angles it started, but it depends on the

length of the pendulum. The longer the pendulum is, the slower the pendulum swings.

This proven that the shorter pendulum would swings faster. As the angle of oscillation

or amplitude increased, the period will also increased. Even though, the greater mass

it brings, the less air friction that will slow the pendulum’s movement, but this matter

does not affecting much in the movement.

Conclusion

In this topic, we are all know that vibration has becomes a highlight in

technology development because it makes the radio and TV works really well. If we

look up again, the fact tells that vibration is a mechanical oscillation of an object that

passes its balance position, could be anywhere, even in a watch. By that, we want to

test it by make a duplicate of a pendulum using a piece of a string and metals as its

weigh. We want to know if the mass that it brings and the length of the amplitude can

affect the vibrations that happen in the pendulum.

As we finished the experiment, the result says that the length of the string and

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the amplitude are the ones that affecting the most because it determines the power that

the pendulum has to bring out the mass. That means that my hypothesis that the

lightest mass would produce the more vibrations is right, but the longer string would

produce more vibrations because it has more power is wrong. The longer pendulum it

is, the more power that it would has, but it ends up with less of vibrations because it

needs a longer time to reach the furthest distance from its balance position.

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Work Cited

Alley, Robert. "What Affects the Swing Rate of a Pendulum?" EHow. Demand

Media, 26 Mar. 2011. Web. 16 Dec. 2012.

<http://www.ehow.com/info_8113160_affects-swing-rate-pendulum.html>.

"How Does Length and Initial Angle Affect the Period in a Simple

Pendulum?"WikiAnswers. Answers, n.d. Web. 16 Dec. 2012.

<http://wiki.answers.com/Q/How_does_length_and_initial_angle_affect_the_pe

riod_in_a_simple_pendulum>.

Morgan, Michael. "Galileo's Pendulum Experiments." Galileo's Pendulum

Experiments. N.p., 17 Apr. 1995. Web. 16 Dec. 2012.

<http://galileo.rice.edu/lib/student_work/experiment95/galileo_pendulum.html>

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