Ex.7. Match the terms and their definitions. Compose 5 sentences with any of them.
| 1 | accumulation | a | the reduction of the amount of smth that is available |
| 2 | amount | b | the quality of doing something well without wasting time, money, or energy |
| 3 | capacity | c | the objects, buildings, natural things etc that are around a person or thing at a particular time |
| 4 | depletion | d | an amount or unit in a measuring system |
| 5 | efficiency | e | a disadvantage caused by someone or something leaving or being removed |
| 6 | friction | f | gradual increase in numbers or amount of smth until there is a large quantity in one place |
| 7 | loss | g | energy that can be used to make a machine work or to make electricity |
| 8 | measure | h | an amount or quantity of something used as a standard of measurement |
| 9 | power | i | the number 1 |
| 10 | surroundings | j | the natural law that prevents one surface from sliding easily over another surface |
| 11 | unit | k | the amount of something that a factory, company, machine etc can produce or deal with |
| 12 | unity | l | a quantity of smth such as time, money or a substance |
Ex.8. Transform the following sentences from Active into Passive.
1. We cannot create energy within the machine.
2. We measure the capacity of a machine by the time rate at which it can do work or deliver energy.
3. A motor, no matter how small, can deliver a large amount of energy if given sufficient time.
4. A force F develops the power P.
5. The power P does an amountof work U.
6. Application of the work-energy method calls for an isolation of the particle or system under consideration.
7. The work – energy method permits the analysis of a system of particles without dismembering the system.
Comprehension check. (Parts 1, 2 and 3.)
Ex.9. Find 14 odd words which shouldn’t be used there.
The choice of a coordinate system is being frequently indicated by the number and geometry of the only constraints. Thus, if a particle is freeto move in space, as if is the center of mass of the airplane or rocket in the free flight, the particle is said to have three degrees of freedomsince three independent coordinates are not required to specify the position of the particle at any an instant. All three of the scalar components of the equation of motion would have to be applied and integrated to obtain the space coordinates as a function as of time. If a particle is constrained to move along a surface, as is in the hockey puck or a marble is sliding on the curved surface of a bowl, only two coordinates are to needed to specify it’s the position, and in this case it is said to have had two degrees of its freedom. If a particle is constrained to move along a fixed linear path, as is the collar sliding along a fixed shaft, its position may to be specified by the coordinate measured along the shaft. In this case, the particle would have only one degree offreedom.
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