- •Part I
- •Text. Physics and physical phenomena
- •Laboratory Exercises
- •Additional Material
- •M. V.Lomonosov
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Measurement of Volume
- •Text. The metric system
- •Dimensions of a Solid Body
- •Laboratory Exercises
- •Additional Material
- •Origin of the Metric System
- •Text. The kinetic theory and the three states of matter
- •3 Not to matter — не иметь значения will make full use — займут
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Text. Mass and weight
- •3. Much, more, the most; little, less, the least; good, bet ter,
- •4, .,. Er than, more ... Than
- •5. At, on, over .., etc.
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Text, force, work, energy and power
- •Exercises
- •Additional Material
- •1. Have supported, has altered....
- •2. Energy can be converted...
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Isaac Newton
- •Text. Heat
- •1. Heat is known to be a form of energy.
- •2. You place, you placed, you have placed. They take, they took, they have taken.
- •3. Newton began to think about heat.
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Text. Transmission of heat
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Good and Bad Conductors of Heat
- •Text. Calorimeters
- •1. It is usual to transfer ...
- •2. There is; is there; there is no ...
- •3. The setting up of ...; the reading of ...
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Text. Wave motion and sound
- •1. It does not move forward but returns again...
- •2. It is evident, it is clear.
- •Exercises
- •Additional Material
- •Text. Light
- •1. It becomes red-hot, it is the reason, it was cold...
- •2. High temperature produced by..., in a substance called... . Exercises
- •Laboratory Exercises
- •Additional Material
- •Text. Reflection and refraction of light
- •1. Do bodies emit? Does he make? Did it represent?
- •2. Have they shown? Had he travelled? Was it reflected? Is he going? Exercises
- •Laboratory Exercises
- •Additional Material
- •Text. Lenses
- •1. After leaving the lens...
- •Exercises
- •Additional Material
- •Text. Simple cell
- •1. The twitching of; the reading of...
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Voltaic Cells
- •Text. The accumulator
- •1. A plate containing, a plate being immersed...
- •2. Achieved by connecting; determined by testing...
- •Exercises
- •Additional Material
- •Text. Principle of electric motor
- •1. They are used to pull...
- •2. When viewed, while doing...
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Electric Bell Circuit
- •Text. Moving-coil ammeter and voltmeter
- •Exercises
- •Laboratory Exercises
- •Additional Material
- •Moving-Coil Galvanometer
- •Text. Electromotive force
Text. Transmission of heat
Heat can be transmitted by conduction, metals being the best conductors; convection, which is taking place only in liquids and gases; and radiation.
What is conduction? When one end of an iron rod is held in a flame, the other end of the rod will soon be too hot to be held comfortable. In some way, the heat is conducted, or led, from оде end of each solid to the other end. The molecules of the rod which are adjacent to the flame receive some of this heat energy, which they transmit along the rod to other molecules. .Such transmission of heat from molecule to molecule is called conduction. Metals, generally are much better conductors of heat than wood or stone.
What is convection? When a portion of water near the bottom of a vessel is heated, it expands and becomes less dense. The denser water from the opposite side of the vessel. flows across and pushes up this less dense water thus setting up convection currents: Convection currents may be set up. in either liquids or gases by unequal heating. By means of such currents heat is transmitted by the movement of the heated masses.
What is radiation? Radiant heat is the name given to heat in the form of rays. A hand held in front of a fireplace is quickly warmed by radiation. We receive heat from the sun the same way. This heat radiation is probably due to the internal motion of the atoms and molecules of the heat-producing body, and travels through space as a wave. Heat radiation is one of several types of wave motion studied in physics, called electromagnetic waves.
Heat radiation is not heat itself, but the absorption of heat radiation produces heat in the absorbing medium. Thus: 1) Radiation can travel
56
through a vacuum. 2) Radiant heat warms only objects on which it falls and which absorb it; it does not heat the "medium" through which it passes.
Listen and read words and word combinations to be remembered: transmit
Transmit [trænz'mit] передавать dense [dens] плотный
conduction [kan'dAkJn] проводимость ray [rei] луч
convection [kan'vekjn] конвекция absorb [ab'so:b] поглощать
radiation [,reidi'eijn] paдиация absorption [ab'so:pjn] no-
rod [rod] стержень глощение
medium ['mi:diem] среда adjacent [a'djeisant] приле- wave [weiv] волна гающий
in some way каким-то путем
convection current конвекционный поток
radiant heat лучистая теплота
heat-producing body тело, производящее тепло
heat radiation теплоизлучение
wave motion волновое движение
Models
1. but, though
It is raining, but he will go out. Though it is raining, he will go out. Heat radiation is not heat itself, but the absorption of heat radiation produces heat in the absorbing medium. Though heat radiation is not heat itself, the absorption of heat radiation produces heat in the absorbing medium.
2. either ... or
The students work either inside or outside the laboratory. Convection currents may be set up in either liquids or gases by unequal heating.
3. too, too much, too many
The bread is too hard to eat. The rod is too hot to be held. The distance is too big to be measured by a ruler. There is too much work for us to finish it today. There are too many problems for us to solve today.
57
4. Convection currents may be set up by unequal heating
It was done by working hard. Knowledge may be acquired by studying. The problem has been solved by com putting.