6.2 Opting out

This last section of the unit contains, I think, some of the most challenging science that you have met so far. Take it slowly, translating all the abbreviations in your head as you come to them (read BAT as ‘brown adipose tissue’, for example) and looking carefully at the graph in Author(s): The Open University

5.2 Body size and metabolic rate

Figure 6 is a slightly more complex graph than those used in S182_1. In particular, the masses of the mammals that are plotted on the horiz
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5.1 Introduction

If you have already worked through S182_1 Studying mammals: a winning design, you'll be aware (from Section 5) that animals break down their food for conversion into usable forms of energy; thus, breakdown of food is sometimes called (as in the commentary to the TV programme) the ‘internal fire’. Fire is a useful analogy because within the body, food is oxidised. This process is comparable to burning, but it is much, much slower and takes place in living tissue. Chemical energy rel
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3.5 Bats

There are two more activities in this section that give you more practice in writing. You will see that you are again given an approximate number of words to aim for in your answer. This number is a guide to the level of detail required – you will often find the same thing done in course assessment questions.
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6.2.3 Measurement of the angular distribution of the 3 K radiation

How are such angular distributions to be measured? One way, of course, is to take a radio telescope and swing it round the sky, taking readings in different directions. But as is clear from Figure 20(a), the atmosphere itself emits microwaves. There is therefore a grave danger, with this method, of picking up different contri
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5.2 The energy of electromagnetic waves

The energy density of an electric field E is

Although we will not prove it in this unit, a very similar result applies to magnetic fields. The energy density of a magnetic field B is

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5.1.3 Getting agreement with Faraday's law

Substituting Equation 7.21 into Faraday's law gives

This shows that a propagating electric wave is automatically accompanied by a transverse magnetic wave. The magnetic field oscillates in the y-direction, which is perpendicular to the direction of propagation and
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4.6 Postscript to Section 4

This section has considered a small number of chemical pollutants of water and has examined what is known about their harmful effects on animals, humans and the environment. You should be aware of a number of important general points that arise from what you have read. First, there is an enormous variety of chemical pollutants; you have read about only a few. Secondly, the evidence that chemical pollutants are potentially harmful is often more convincing from studies of animals than it is fro
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4.3 Mercury

Mercury is a naturally occurring metal which, in its pure form, is not particularly toxic. Under normal conditions of temperature and pressure, it is a silvery-white liquid which readily transforms into a vapour. When vaporised, it enters the atmosphere, remains there for a long time, and is circulated globally (WHO, 2005b). Through chemical reaction and precipitation it enters freshwater lakes and rivers, where it accumulates in the sediments at the bottom. Here it is transformed by bacteria
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3.6.2 Exponential increase: bacteria

Bacteria are single-celled organisms. Many different types of bacteria exist and they populate almost every environment on earth, from deep oceans to soil to human intestines. Several bacteria are beneficial to us: for instance, our gut bacteria can help to break down foodstuffs that we would otherwise find difficult to digest. However, some bacteria produce harmful toxins and if they grow in an uncontrolled way in our bodies this can have serious health consequences.

If a bacterium is
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3.6.1 Radioactivity and bugs!

Many natural processes involve repeated doublings or halving at regular intervals. You may have come across this already in your work, in the context of bacterial growth or radioactivity. In this section, we are going to look in more detail at bacterial growth and radioactivity and we will be using graphs to examine how the numbers of bacteria or numbers of radioactive atoms change over time.


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2.2.2 Precision

Measuring the same sample should give the same result every time if the equipment is precise. In practice, the information displayed by a measuring device can depend on several factors (such as temperature and humidity) and can drift slightly over time. Nevertheless, during the time it takes to complete a measurement sequence, all measurements ought to remain within a specified, small margin of error, often marked on the equipment. We will see later on, in Author(s): The Open University

1.11 Addition and subtraction in practice – fluid balance

A common healthcare example that uses addition and subtraction involves calculating the fluid balance of a patient.

Fluid balance is a simple but very useful way to estimate whether a patient is either becoming dehydrated or overfilled with liquids. It is calculated, on a daily basis, by adding up the total volume of liquid that has gone into their body (drinks, oral liquid medicines, intravenous drips, transfusions), then adding up the total volume of liquid that has come out of their
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1.5 Rounding to decimal places

Sometimes the result of a calculation gives a number with lots of decimal places – far more than you need or could reliably measure. For instance, suppose a patient is required to receive 5 ml of medicine a day, evenly spaced in three injections. How much medicine should they be given in each dose?

To divide the 5 ml of medicine into three equal parts would mean measuring out 5 ÷ 3 = 1.6666 ml (where the 6s keep repeating, or recurring indefinitely). It's not realistic or feas
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Introduction

This sample of S110 material is taken from Module 2, entitled Using numbers and handling data. As you read the material, bear in mind that it is taken from a work-based course, designed for those who are employed in the health services, perhaps as a paramedic or as operating theatre staff. If you were a student on the course, you would have an OU tutor to help you, plus a work-based mentor supplied by the employer – normally the NHS. The aim is to use the workplace as a teaching aren
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5.2 Precambrian and Lower Palaeozoic Basement

The Precambrian and Lower Palaeozoic Basement of the British Isles is a series of nine discrete, exotic terranes whose boundaries are fault systems that have undergone large but usually unknown amounts of lateral and vertical movement over time (Figure 11 and Author(s): The Open University

3.7 Moon39: Apollo 14 station C

The panorama was collected by Alan Shepard at station C-Prime. (QuickTime, 500KB, note: this may take some time to download depending on your connection speed)

3.4 Moon36: Apollo 12 station 2

Pete Conrad took this pan early in EVA-1 from a position due west of the Lunar Module. Al Bean can be seen in several frames taking documentation photos of the Solar Wind Collector (SWC) that he has just deployed. (QuickTime, 500KB, note: this may take some time to download depending on your connection speed)

2.3 Missions to the Moon

David A. Rothery Teach Yourself Planets, Chapter 6, pp. 66–75, Hodder Education, 2000, 2003.

Copyright © David Rothery

The Moon was the first extraterrestrial target for space missions. Probes have been directed towards it since almost the very dawn of the space age (see below), and it was the main focus of the 1960s–1970s ‘space race’ between the USA and the then Soviet Union. In the end, only NASA attempted to put people on the Moon, and the six suc
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3 What are compounds?

Activity 1: Elements and compounds

0 hours 10 minutes

Click on the video clip to watch Elements and Compounds, which focuses on water and its constituent elements.

Click below to v
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