6. Match the notions and their definitions.

1) shearing sfress, compressive sfress, stress, strain, unit strain, tensile stress, total strain is referred to as / is defined as / is known as / is caused by.

2) resistance to external forces; a normal stress when the external and internal forces are perpendicular (normal) to the cross-sectional area under con­sideration; strain caused by equal and opposite pushes F at the ends of the rod; stress that occurs because of the sliding of the above and below layers of the solid; the total change in the size or shape of a body; the total change in the size or shape of the body divided by its original size or shape; the deformation of a body that results from an applied force.

7. Make up sentences with the negative words using the prefixes dis-, in-, un-.

place, definite, arrange, suitable, usual, stretched, compressed, sheared, twisted, bent, combined, efficient, equal, accurate, expensive, defined, stressed, strained, deformed, connect, divided, variably, loading, elastic.

8. Group the synonyms.

cause, flexible, quality, outside, form, area, internal, deform, use, apply, change, exert, characteristics, constant, formless, stress, square, distort, inside, shapeless, tension, elastic, make, space, shape, external, territory, property, permanent, strain.

9. Explain the following derivatives with the same root denoting a person, object, state, action, process, result, property, phenomenon, science.

mechanic – mechanics – mechanical – mechanically – mechanize – mechanization – mechanism, physics – physical – physicist, apply –

applicable – application – applied – applying, form – formation – deformation – deformed, press – pressing – pressed – pressure – depressed – depression.

10. Ask each other about the characteristics of the physical notions.

Example. Distance is measured in kilometres. Distance is expressed with letter S. This value is obtained by equation____.

length, width, hight, depth, resistance, stress, velosity, tention, voltage, resistance, deformation, pulling, bending, shearing, twisting, stretching, strength, tensile stress, compressive stress, shearing stress, internal force, external force, strain.

11. Make up dialogues on the following topics.

1) The strength of materials, 2) Stresses and strains, their mathematical expression and practical illustrations.

Example. The engineers knew that the machine worked / had worked / would work well.

A. We know that / I wonder if / could / will you tell me / do (would) you

mind telling me / I move that / I am sure that / may I ask you / it is a problem if / it is quite clear / it is doubtful whether / it is proved.

B.The speaker said / agreed / assured / objected that / wondered if / proved that / doubted / told us / asked / answered / what / why / how / where / who / when the material was suitable for the detail / machine, the metal proved reliable, the design is being developed now, this detail will wear with time / quickly, clutches are not used there, they applied connectable joints, slight deformation will not influence the machine part, additional loading can cause fracture and damage.