Exercise 2 . Find the synonyms to the following words in the text.

1. to perform (2)                                 4. different (1)                                  7. due to (2)

2. to deal with (3)                          5. quantity (4)                                   8. have (1)

3. defined (4)                                 6. get (2).                                          9. basic (2)

                                                                                                                     10. mean (adj.) (3)

Exercise 3. Find the correspondence:

1. nearly                                                                     1. в межах, у рамках

2. although                                                                 2. обидві (системи)

3. still                                                                         3. завдяки

4. almost                                                                    4. такі, як

5. while                                                                      5. хоч

6. thanks to                                                                     6. в той час, коли

7. within                                                                     7. або…або… 

8. such as                                                                    8. майже                                                                                    

9. either…or…                                                           9. тільки

10. both (systems)                                                          10. досі

 

Exercise 4. Define the abbreviations:

1 the SI; the USA ;cc; ft ; gr; kg; lb; yd ;m.; the MKS; the CGS system. 

 

Exercise 5. Say if the statements are true or false:

1. The British and American scientists use primarily the Common System.

2. Basic units in two main systems of measurement are not the same, but the basic unit of time is the same in both systems.

3. The advantage of the metric system is its inner logic and order.

4. All conversions of one unit to another in the metric system are very simple operations.

5. Both the MKS and the CGS systems are in current use.

 

Exercise 6. Complete the sentences choosing the right variant:

1. In the metric system the main unit of distance is…

a). the kilometre

b). the metre

c). the centimetre

 

2. In the English System the unit of mass is…

a). the gram

b). the pound

c). the foot

 

3. The Common System is the official one in…

a). India and Persia

b). the USA and the UK

c). China and Japan

 

4. …possesses simple and logical relationship among its units.

a). the MKS system

b). the SI

c). the CGS system

 

5. Conversions of one unit to another within the metric system can be carried out by…

a). multiplying the unit by 10

b). shifting a decimal point

c). multiplying the unit by some power of 10

 

Exercise 7. Answer the following questions:

1. What are two main systems of measurement today? Where are they used?

2. Which one of mentioned above systems is more advantageous?

3. What is time as physical concept with its unit related to?

4. How is the unit of mass defined in the SI?

5. What units are the quantities such as force and energy measured in?

 

Exercise 8. Examine the usage of two main systems of measurement.

Exercise 9. Define the main units of distance, time, mass in both systems of measurement.

 

Exercise 10. Prove that metric system has more advantages than the Common one.

 

Exercise 11. Describe how all conversions of units within the metric system are performed.

 

Exercise 12. Explain why some physical concepts must be defined in terms of certain laws of physics.

 

Exercise 13. Discuss the text according to the points:

1. Two main systems of measurement.

2. The advantages of metric system.

3. The MKS system and the CGS system.

4. The main concepts and their units in the Common System and the SI.

 

                                                      Notes:

1. to possess relationship –           мати стосунок

2. multiply –                                 множити

3. shift –                                       зсув, зміщення

4. a decimal point –                           десяткова кома

5. mean solar day –                           середня сонячна доба

6. exclusively –                                 винятково

7. value –                                          величина, значення

8. conversion –                                  перетворювання

9. the former -                              перший

10. the latter -                                   останній.

 

 

LESSON 2

MECHANICS

Key terms: motion, mechanics, kinematics, dynamics, acceleration, free fall, distance, displacement, speed, constant speed, average speed, velocity, constant velocity

1. The motion of bodies - sailboats, automobiles, rockets, the Sun or the Moon - is an inescapable part of everyday life. Mo­tion is defined as the movement of an object, or any of its parts, from one place to another. The study of the motion of objects and of the forces that affect their motion is called mechanics. Mechanics is divided into two distinct categories: kinematics and dynamics. Kinematics is the description of the motion of objects without considering the cause of the motion. Dynamics deals with examination of the causes of the motion of objects.

2. The most common example of motion with nearly constant acceleration is that of a body falling towards the earth. In the absence of air resistance it is found that all bodies, regardless of their size, weight or composition, fall with the same acceleration at the same point of the earth's surface, and if the distance covered is not too great, the acceleration remains constant throughout the fall. This ideal motion, in which air resistance and the small change in acceleration with altitude are neglect­ed, is called free fall.

3. The acceleration of a freely falling body is called the accel­eration due to gravity and is denoted by symbol g.

4. The length of the path travelled by an object as it moves from one location to another is called distance. The change in position of an object is called its displacement.

5. Anything that moves takes a certain amount of time to trav­el a given ^distance. Speed is defined as the distance travelled per unit time. An object that travels the same distance every second has a constant speed. The symbol for constant speed is v. The speed of light in a vacuum is constant. At this speed it takes light from the sun about 8 minutes to reach the Earth.

6. It is difficult to drive a car or to walk at a constant speed all the time. Suppose that you are walking 2.0 km to your home. You walk the first kilometre in 10 minutes and the next kilome­tre in 20 minutes. You walked at a slower speed during the second kilometre than the first. Average speed is a useful quan­tity for describing the motion of objects that change speed. Average speed is calculated by dividing the total distance trav­elled by the time taken to travel that distance.

           7. Many people use the terms speed and velocity interchange­ably in everyday language. However, they have very different meanings in physics. Velocity describes how fast an object is moving and its direction. It is defined as the displacement (change in position) of an object per unit time. An object that has a constant speed and a constant direction has a constant velocity.

 

 

Exercise 1. Give the English equivalents to the following words and word-combinations:

1. рух                                                                                   6. вага та склад

2. сили, що впливають                                                       7. поверхня Землі

3. прискорення                                                                   8. відстань та переміщення

4. опір повітря                                                                    9. висота

5. відсутність                                                                     10. пройдена путь.

 

Exercise 2 . Find the synonyms to the following words in the text:

1. reason (1)                                                            6. unchangeable (2)

2. place (4)                                                              7. pay no attention to (2) 

3. imagine (6)                                                          8. not likely to be achieved (2)

4. count (6)                                                              9. material thing (1).

5. quickly (7)

 

Exercise 3. Say if the statements are true or false:

1. An object in motion is always affected by some forces.

2. Mechanics deals with the motion of objects.

3. Velocity describes the change in position of an object for a certain period of time.

4. Acceleration due to the gravity is constant.

5. The symbol for constant speed is g.

 

Exercise 4. Choose the definition to the words:

1. speed                                                            1 the acceleration of freely falling body             

2. mechanics                                                    2 movement of an object from one place to another.

3. motion                                                            3 ideal motion     

4. free fall                                                        4 the description of motion without considering its cause.            

5. kinematics                     is defined as… 5 the change in position of an object

6. distance                                                        6 the distance traveled per unit time

7. dynamics                                                      7 the study of motion of objects and of the forces that affect their

                                                                                                                                                                      motion 

8. acceleration due gravity                                8 the length of the path traveled by an object

9. displacement                                                  9 examination of the causes of the motion of objects                                                                               

10. velocity                                                         10 the displacement of an object per unit time                                                     

                                                                                

                                                                          

Exercise 5. Answer the following questions:

1. What is the speed of light?

2. What is the subject-matter of mechanics?

3. It is difficult for objects to travel with the constant speed, is not it?

4. What is more important for the division into categories of mechanics: the motion of objects itself or its causes?

5. What are the causes of any motion?

 

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