Vocabulary notes

far-reaching, adj далекосяжний

the finest clocks найточніші годинники

to provide (smb with smth) забезпечувати (когось чимось)

it is through our

understanding саме через наше розуміння

hawk, n [ho:k] орел, яструб

pendulum, n ['pendjulam] маятник

equilibrium, n [akwi'libriam] стан рівноваги

frequency, n ['fri:kwensi] частота

to occur = to happen траплятися

LEXICAL EXERCISES

I. In group В find Ukrainian equivalents to these word combinations from group A.

A. Transfer of vibrations; 'transparency of objects; to probe the universe; sub-atomic particles; at a constant rate, a freely vibrating pendulum; regular intervals; distant galaxies; periodic motion; repeated pattern; transverse (longitudinal) vibrations; maximum distance; horizontal (vertical) displacement; the time required to complete 1 cycle; specific frequency; to compare vibrations; identical amplitude; the same (opposite) phase.

B. Час, необхідний для завершення одного циклу; подібні амплітуди; однакова (протилежна фаза); характерна частота; горизонтальне (вертикальне) зміщення; максимальна відстань; поперечні (поздовжні) коливання; зразок, що повторюється; передача коливань; прозорість об’єктів; регулярні проміжки; з постійною швидкістю; маятник, який вільно коливається; досліджувати всесвіт; частинки, менші за атом; віддалені галактики; періодичний рух; порівнювати коливання.

II. Read and translate the derivatives of these words. Define, to what part of speech they belong.

'frequent - 'frequency - frequently - infrequent

'period - peri'odical - perio'dicity

place - replace - displace - displacement

vib'rate - vibration - vibrational - vibrating

'atom - a'tomic - ,sub-a'tomic - 'atomize

de'termine — determi'nation - determined - determining

trans'parent — trans'parency - trans'parently

'regular - regularity - 'regularly - ir'regular

ob'serve - observation - observatory - observing - observable

,indi'cate - indi'cation - in'dicative - indicating - indicated

com'pare - 'comparable - com'parison - un'comparable

III. Match the synonyms in groups A and B.

A. to apply, concept, to provide, to probe, distant, by means of, to observe, type, regular, the maximum, to require, to complete, to occur, generally, to allow, specific, identical.

B. usually, to happen, to finish, to need, the greatest, correct, pattern, to watch, to permit, characteristic, the same, through, far-off, to investigate, to give, idea, to use.

CONVERSATIONAL PRACTICE

Talk with your groupmates about one of the topics concerning vibrations and waves. Here are suggested some topics for discussion.

The role of vibrations in nature.

How do we obtain our knowledge of galaxies?

Transverse and longitudinal vibrations.

The concept denoted by symbol T.

What properties does the term «phase» describe.

Examples of the same and different phases.

TASKS

Text review.

a) Describe two examples of transverse vibrations not mentioned in the text.

b) Describe two examples of longitudinal motion not mentioned in the text.

A bird flaps its wings 10 times in 15 seconds. Calculate:

the period of its wing beat.

the frequency of its wing beat.

The electrons in an alternating current vibrate with a frequency of 60 Hz.

What is the period of that vibration?

How many times do these electrons reverse each second?

The word «transverse» comes from the Latin word trans, which means «across». Give three more examples of words that also use «trans» in this way.

MULTIPLE CHOICE

Each of the following statements is followed by five responses. Choose the correct response in each case.

1. A vibrating object completes 20 cycles in 80 s. What is its frequency?

a) 0.25 Hz b) 4.0 Hz

c) 60 Hz d) 1.6 x 10 Hz

e) l.OxlO2 Hz

2. If the frequency of a metronome is 0.20 Hz, what is the period?

50 s b) 5.0 s c) 20 s

0.50 s e) 0.20 s

PROBLEMS

As water waves approaches the beach, their wavelength decreases. If the frequency of the waves does not change, what must be happening to their speed? Explain.

Water waves near the base of a cliff are often of greater amplitude than those farther out from the cliff. Explain.

I. Read text 3 without consulting the dictionary and give its main idea.