Английский язык. Ильичева Н.А - 29 стр.

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2. A weight lifter holds 300 1b over his head. Did he do work on the
   weights?
a) Yes, he did, because he pushes his weight up with an equal and …… force.
   The distance parallel to the applied force was the …… . So he did work
   against …… .
b) The weight lifter didn’t do any work because he didn’t …… his weight
   through a horizontal distance.

3. Persons A and B do the same job, but B takes a longer time. Who
   expends the greater amount of power?
a) B expends the greater amount of power because he works longer.
b) A ……. the greater amount of power because the same amount of work is
   done in each case. Besides, power is the …… of work. To calculate power,
   we must …… work by the time required to do it.
4. What is the unit for which we are charged by the electric company?
a) We are paying for energy (……).
b) We are paying for ……, so we are charged for watts.

14. Read the dialogue between Peter and his mother filling in the words
   form the list:
consume, multiply, electric, amount, compute, watts, time

M.: I’m worried about the motor you bought yesterday, Peter. I think our a)
………. Bills will be very high as soon as start working on it.
P.: Don’t be afraid, mum. My motor doesn’t b) ……… much energy. It’s a one
horsepower motor.
M.: What does it mean?
P.: One horsepower is 746 W c) ………, or about 0.75 kW. Do you remember
how to d) ……… the amount of energy consumed in a home?
M.: Not exactly.
P.: Energy is power times e) ……… . The cost of electricity is 10 c per kWh.
So, to run the motor for 10 hours will cost only 75 c.
M.: As far as I understand, we first multiply o.75 kW by 10 to compute the f)
……… of energy consumed in 10 hours, which is 7.5 kWh, and then we g)
……… this figure by 10 because he cost of electricity is 10 c per kWh. That’s
pretty cheap.

15. Fill in the missing letters in the following words to five different forms
   of energy other than kinetic and potential energy:
H _ _ T, _ _ DIANT, SO _ _ D, C _ E _ I _ AL, NU _ _ EAR.