Read the text and find new words from the text.
Before-Reading
PROPERTIESOFMATERIALS
Exercise13. Translate into English using Infinitive Constructions.
Exercise12. Make sentences using the words and word combinations from columns. Translate them into Russian.
He was not the man to buy.
There was nothing to raise his hand.
The river is dangerous to rely on.
He was the last to lose.
Who was the first to pay for the purchase.
These are the shoes to speak of.
Here is the money to bathe in.
There is no time to arrive.
Образец: Мне было трудно понять это.-It was difficult for me to understand it.
1. Майку было трудно просить у Тома работу. 2. Томпсону было легко выиграть соревнование. 3. Джемме было легко поверить, что Артур предатель. 4. Мне было неприятно смотреть на него. 5. Для нас было очень важно обсудить этот план.
Unit14
1. Discuss the following:
* The development of the metallurgical and machine-building industry made possible mass production of materials, did not it? Prove your own point of view.
* What advantages do all materials have?
2. Match the following words with their Russian equivalents:
* Ensity • вес
* weight • количество
* a volume • объем
* an amount • плотность
* stiffness • жесткость
* rigidity • твердость
* a force • сила
* strength • прочность
3. Make up your own sentences with the following words:
density (плотность), weight (пес), volume (объем), stiffness (жесткость), to yield strength (поддерживать опору,), fracture (предел текучести), break (перелом, излом), ductility (ковкость),
brittle (хрупкий), toughness (прочность), resistance (сопротивление), crack (трещина), creep resistance (устойчивость к ползучести), gradual (постепенный), permanent (постоянный), engine (двигатель).
While-Reading
2. Read the text. Find and translate all the sentences, containing the following words:
* engine
* permanent
* change
* shape
* crack
* creep
* resistance
* gradual
* toughness
* brittle
* ductility
3. Reading for specific information. Read the text, choose a right word.
4. Reading for. general meaning. Read the text and answer the following questions to the text:
• Is density (specific weight) the amount of mass in a unit volume?
• Is it measured in kilograms per cubic meter?
* Is .density important in any application where the material must not be heavy?
* Is stiffness (rigidity) a measure of the resistance to deformation such as stretching or bending?
* Is strength the force per unit area (stress) that a material can support without failing?
* Is toughness the resistance of a material to breaking when there is a crack in it?
* Is creep resistance the resistance to a gradual permanent change of shape?
Density(specific weight) is the amount of {mass, quality) in a unit volume. It is measured in (kilograms, distances) per cubic meter. The density of water is 1000 kg/m3 but most {materials, kinds) have a higher density. Aluminium alloys, with typical densities around 2800 kg/m3 are considerably less dense than steels, which have typical densities around 7800 kg/m3. (Density, class) is important in any application where the material must not be heavy.
Stiffness(rigidity) is a (measure, glass) of the resistance to deformation such as stretching or bending. The Young modulus is a measure of the resistance to (simple, different) stretching or compression. It is the ratio of the applied force per unit area (stress) to the fractional elastic deformation (strain). (Stiffness, Density) is important when a rigid (structure, house) is to be made.
Strengthis the (force, column) per unit area (stress) that a material can support without failing. The units are the same as those of stiffness, but in this case the (deformation, local) is irreversible. The yield strength is the (stress, point) at which a material first deforms plastically. For a (metal, water) the yield strength may be less than the fracture strength. It is the (stress, metal) at which it breaks. Many materials have a higher (strength, work) in compression than in tension.
Ductilityis the ability of a (material, column) to deform without breaking. One of the great (advantages, styles) of metals is their ability to be formed into the (shape , part) that is needed, such as car body parts. Materials that are not ductile are brittle. Ductile materials can absorb energy by (deformation, assignation) but brittle materials cannot.
Toughnessis the (resistance, deformation) of a material to breaking when there is a crack in it. For a material of given toughness, the stress at which it will fail is inversely proportional to the square root of the size of the largest (defect, form) present. (Toughness, importance) is different from strength. For example, the toughest steels are different from the ones with the highest tensile strength. (Brittle, easy) materials have low toughness. For example, glass can be broken along a chosen line by first scratching it with a diamond. Composites can be designed to have considerably greater (toughness, flexible) than their constituent materials. The example of a very tough composite is (fiberglass, idea) that is very flexible and strong.
Creep resistanceis the (resistance, part) to a gradual permanent change of a shape, and it becomes .especially important at higher (temperatures, speeds). A successful research has been made iri (materials, classes) for machine parts that operate at high temperatures and under high tensile forces without gradually extending. For example, they can be the (parts, ways) of plane engines.
6. Read the text again and complete the following sentences:
* Aluminium alloys, with typical densities around...are considerably less dense than steels, which have typical densities around...
* ...is important in any application where the material must not be heavy.
* The Young modulus is a... to simple stretching or compression.
* It is the ratio of the applied force per unit area (stress) to the...
* The yield strength is the stress at which a ...
* For a metal the yield strength may be which the stress at which it breaks is; many materials have a... tension.
* One of the great advantages of metals is... such as car body parts.
* Materials that are not ductile are...
* Toughness is the... of a material to breaking when there is a crack in it.
* ...is a measure of the resistance to deformation such as stretching or bending.
7. Read the following statements and say whether they are true or false. Correct the false statements:
* Density (specific weight) is not the amount of mass in a unit volume.
* Aluminium alloys, with typical densities around 3000 kg/m3 are considerably less dense than steels, which have typical densities around 7800 kg/m3.
* Density is not important in any application where the material must not be heavy.
* The Young modulus is a measure of the resistance to simple stretching or compression.
* It is-the ratio of the applied force per unit area (stress) to the fractional elastic deformation (strain).
* Strength is the force per unit area (stress) that a material can support without failing.
* Many materials have not a higher strength in compression than in tension. Ductility is the ability of a material to deform without breaking.
* Toughness is the resistance of a material to breaking when there is a crack in it.
* It is measured in a kilogram per cubic meter.
8. Match the parts of the following sentences:
• Density • is the resistance of a material to breaking when there is a
crack in it.
* Stiffness • is the amount of mass in a unit volume.
* Strength • is a measure of the resistance to deformation such as
stretching or bending.
• Ductility • is the resistance to a gradual permanent change of
shape.
• Toughness • is the ability of a material to deform without breaking.
• Creep resistance • is the force per unit area that a material can support
without failing.