6.2 Natural frequency of free oscillations

Most of us have a fairly accurate understanding of what is meant by resonance – it's what causes a bell to continue to make a sound long after it has been struck. Yet this is just one example of resonance, a phenomenon that occurs in nature in a surprisingly large number of places.

It is all to do with the reversible transfer of energy from one form to another in a system. The common feature associated with mechanical systems that are able to store energy by oscillating is that they h
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5.2 Material comparisons

I want to depart from the specific example of the bicycle to make some more general points.

In most simple structural analysis the self-weight of the structure is ignored, as it is considered to be small in comparison with the loads carried. However, as an illustration of engineering practice in the search for efficient structures to employ in product design, it is worth examining how the strength and weight of particular materials compare.

These comparisons are illustrated throug
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2.5 Making multiple copies

Berliner was aware that Edison had problems duplicating cylinders. Initially copies were made from a master cylinder using a mechanical engraving process. Unfortunately this method caused the master cylinder to wear out after making just a few copies, so performers had to be asked to record several masters to ensure enough cylinders could be duplicated. An improved recording system allowed multiple master cylinders to be made by feeding several recording phonographs from one horn, but the cyl
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1 Capturing sound

Have you ever listened carefully to a recording of your own voice?

In this first activity, I want you to make a short recording of your voice.

Activity 1 (Optional)

Note: This optional activity requires the use of a
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Acknowledgements

The following material is Proprietary and is used under licence:

Text

Naughton, J. (1998) ‘Arts: Internet: It's free and it works. No wonder Bill Gates hates it’, Observer, 8 November 1998, © Guardian News and Media Ltd 2005;

Wilkins, E. (1994) ‘Rescued from £1 a day for girl's upkeep’, The Times, 31 January 1994. Copyright © Times Newspapers Ltd 1994;

‘Agency demands 1p from father’, The Time
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3.2 Being aware of the constraints and possibilities of the observer

It is often claimed that the essence of a systems approach is that of seeing the world in a special way. This immediately prompts the question of what is meant by the phrase ‘seeing the world’. Because we live so intimately with the world of objects, categories and people and phenomena, we tend to think our own way of seeing the world is the only way, or even of thinking, ‘Well that is my view because the world is like that’. Actually, your view is special in several separate ways.
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11.5.5 Chance

Another important source of inventions and scientific discoveries is chance, which is strongly associated with acts of insight. As well as the sort of painstaking work that either precedes an invention or goes into the steady improvement in performance, in the development of most inventions there's a moment when chance plays a part. Often people are looking for one thing but find another – perhaps working on one technology when they stumble on the principles behind another. The skill of the
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5.14 Compact fluorescents and new developments

In the case of the electric light there were a series of incremental product innovations (metal filaments, gas filled bulbs, frosted bulbs) as well as process innovations (some of which were mentioned above), which steadily improved performance and reduced price until, by the 1930s, the incandescent light was mature and diffused in many nations.

Then in the mid-1930s a new invention appeared that was to challenge the incandescent lamp – the fluorescent lamp. This was the culmination o
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4.1 An explanation

I will now elaborate on my answer from Exercise 1. I'm doing this because my internet search revealed more than I've written in the above answer, and to show that the invention of the telephone and its use by consumers is not as plain and simple as you may think. You we
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1.2.4 Conveying information to others

Diagrams are used extensively in most types of texts, but why do authors use them? There are two main reasons:

  • to illustrate what something looks like;

  • to demonstrate how objects or ideas or quantities are organised or related.

But there is also a subsidiary reason I hinted at. Authors also use diagrams:

  • to decorate and enhance the text to make it more pleasing to read.


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Learning outcomes

After reading this unit you should be able to:

  • appreciate diagrams as a powerful aid to thinking and acting;

  • distinguish between systems diagrams and diagrams helpful in systems work;

  • demonstrate sufficient skills to ‘read’ and ‘draw’ a wide range of diagrams, following given conventions, that help improve your understanding of a situation;

  • select diagrams suited to the needs of the situation you are investigating and the purp
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2 New products – old failings

This section introduces product ‘usability’. It offers a case study of a vegetable peeler to illustrate how usability issues exist alongside other important concerns in the product development process.

If you look around high-street or shopping-mall stores, you cannot help but notice the number and variety of new products on offer. This year's washing machine or dishwasher, stylish furniture, multi-feature telephones, audio systems, DVD players, digital cameras and camcorders, all b
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2.7 Infiltration

Entry of precipitation through the soil surface and on downwards, by gravity, is known as infiltration. The rate at which this process can take place is governed by the permeability (a measure of the ease with which water can flow through the subsurface layer) and by the existing degree of saturation of the soil. Infiltration can be impeded by outcropping impermeable rocks or by paved areas, and also by the presence of finegrained soils with a low permeability (such as clay). At certain times
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3.5 Design of the bridge

The design of the original structure was governed by applicable standards in 1926. The official inquiry found that the design and build fell within those limits, the most important being the allowable stress in the eye-bar chain of 345 MPa. The steel was to be made with a maximum elastic limit of 520 MPa, with a safety factor on the strength of the steel of 2.75. It was argued at the time that over 70 per cent of the load was from the self-weight of the structure. Other suspension bridges of
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Learning outcomes

After you have completed this unit you should be able to:

  • differentiate between and describe dissolution, degredation and corrosion as they affect the deterioration of structural materials;

  • predict electrochemical behaviour between dissimilar metals;

  • explain galvanic corrosion in terms of the electrochemical series;

  • distinguish between the hoop and longitudinal stresses in a pressure-vessel wall, and specify them in terms of the press
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1.1 Creating characters

Activity 1

Click on 'View document' below to read the first few paragraphs from Novakovich's chapter on ‘Character’.

Learning outcomes

By the end of this unit you should:

  • have begun to identify your own strengths and weaknesses as a writer of fiction;

  • have developed a general awareness of fiction writing;

  • have developed a basic vocabulary to discuss fiction.


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8.4 Hinduism in eastern India: religion in Calcutta

The Hinduism of Bengal, as in other regions of India with their own languages and distinctive historical traditions, has absorbed and retained many local elements which make it peculiarly the Hinduism of Bengal. The city of Calcutta has exerted its own considerable influence upon the surrounding region. Calcutta, the capital of West Bengal, was founded in 1690 originally as a British trading post on the Hugli, a stretch of the Ganges (or Ganga), a river sacred to Hindus (see Author(s): The Open University

7.4 Religion: true or false?

I noted earlier that differences between the truth claims made by religions has led those who practise Religious Studies to avoid premature judgements when dealing with questions relating to the truth and value of particular religions. By seeming to by-pass truth claims, you may feel that what I have been describing as Religious Studies avoids what many would regard as the purpose of religion – to deal in truths. This is a difficult area to cover briefly, but let me at least try to explain
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