Проверочная работа за раздел "Работа и энергия"

Verification work for the section “Work and energy”

1.a) Read the text and choose the correct name

1.       Kinetic energy

2.       Power

3.       Work and Power

4.       Work and energy

5.       Efficiency

The ________which is accomplished by a _________  is called the _________  work is measured in a _________.

The work of the force that is committed per unit time is called the  ________ .

________ is equal to the ratio of useful work and to spent or useful power and to spent.

The thing has energy if it is able to do the work any thing that moves has __________.

The potential energy is determined by the ______________ of things.

1.b)  Read the text again and complete it with the correct words and phrases in the box

_________________________________________________________________________________

mechanical work     constant force     work of displacement  Joule    power     Efficiency     kinetic energy      relative position

_________________________________________________________________________________

1.c) Look at the highlighted word and phrases.

       Use your dictionary to look up their meaning and pronunciation.

1.d) listen and repeat new words and phrases . Useful words and phrases. Learn these words and phrases.

Mechanical work [mɪˈkænɪkəl wɜːk]

work of displacement [wɜːk ɔv dɪsˈpleɪsmənt]

constant force [ˈkɔnstənt fɔːs]

Joule [ʤuːl]

Power [ˈpaʊə]

Efficiency [ɪˈfɪʃnsɪ]

Kinetic energy [kaɪˈnetɪk ˈenəʤɪ]

Relative position [ˈrelətɪv pəˈzɪʃn]

2.a) Copy and complete the table

example	Renewable Energy sources	Non-renewable Energy sources
	Wind	Natural gas

2.b) Copy and complete the energy flow diagram for a power station

Thermal    chemical    electricity    movement

→ furnace and boiler →  → turbine → → generated→ 

2.c) Answer the questions

1. Write down three types of power that use a turbine driven by steam 

2. Write down three ways of generating electricity that use turbines driven by air or hot gases (not steam)

3. Which two types of power station use a turbine driven by water?

4. How can you produce electricity without using a turbine or a generator at all?

3.a) Mark the sentences T(true) and F ( false)

1. The kinetic energy and potential energy are always the same (F)

2. Work is equal to the change in energy (T)

3. Work and energy are measured identically (T)

4. Potential energy is the energy of moves (F)

5. To find the power, you need to know efficiency  (F)

3.b) There are some mistakes. Find them.

1. A=mυ

2. N=A/t

3. Ek=mυ/2

4. Ep=mgh

5. [N]- m

6. [A]- J

7. [E]- J

8. η= FS

9. A = mg(h2-h1)

10. A=kx²/2

4. Solve the task

a) The force of 20 Newtons is applied to compress the spring by 3 centimeters. Find the potential energy of the spring.

b) The athlete raises the barbell and commits 5 joules in 2 seconds. Find its power.

c) The mechanical shovel has a power of 5kW and can raise 144 tons of sand to a height of     10 m in 2 hours. Find the efficiency.

5. Write your opinion about alternative types of energy (25-35 words).