Дидактические материалы для работы с учебным пособием С.В. Андриановой «English Thesaurus of Student-Physicist». Учебно-методическое пособие
.pdf8.What kinds of waves do you know? (a pulse wave, a continuous wave, a sinusoidal wave /← these are transverse waves/ and a longitudinal wave)
9.What is the energy of a wave proportional to? (It’s proportional to its amplitude, squared.)
10.What is constructive interference? (It’s when the waves build on each other. When the two pulses overlap, they’ll combine to make one crest, with a higher amplitude than the original ones.)
Exercise 3. Give examples of using constructive and destructive interference to our advantage. (Noise-canceling headphones, for example, work by analyzing the noise around you and generating a sound wave that destructively interferes with the sound waves from that noise, canceling it out.)
Exercise 4. Are the following statements true (T) or false (F)?
Multiply the wavelength by the frequency, and we get the wave’s speed. (T)
All waves transport energy as they travel. (T)
Elastic potential energy is the energy stored in a stretched or compressed spring. (T)
If the fluid viscosity is low the system is said to be overdamped. (F) /high viscosity/
Two traveling waves can meet and pass through each other without being destroyed. (T)
Exercise 5. Give your comments on the following statement, speak about advantages/disadvantages; your attitude; history
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of the invention; the way and prospects of using; being ecological-friendly etc.:
High level of noise is a problem for cities. What can be done to reduce it? What useful devices that may help can you think of?
Unit 14
SOUND
Exercise 1. Follow the link and watch the video:
https://www.youtube.com/watch?v=qV4lR9EWGlY
Exercise 2. Answer the questions:
1.What is sound? (a wave which travels through a medium /like air or water/)
2.What kind of wave is sound? (longitudinal)
3.What happens when we heard a sound? (pressure waves come through, eardrum vibrates)
4.What is the other description of sound? (moving particles in the air –displacement wave, pressure waves)
5.Why do older people hear badly? (They lose cells that help to detect sound.)
6.What sound do we call:
ultrasonic (too high);
infrasonic (travel long distances)?
7.What in another characteristic of sound? (loudness)
8.What is the intensity of a wave equal to? (proportional to the wave’s amplitude squared)
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9.What do you know about decibels? (We use them instead of direct measuring the loudness of sound.)
10.What is the Doppler effect? (As a source of sound moves toward you, the pitch of the sound you hear increases.)
Exercise 3. Give examples of using sounds in medicine or home appliances. /ultrasonography apparatus, headphones/
Exercise 4. Are the following statements true (T) or false (F)?
Audible waves are transverse. (F) /longitudinal, 20 – 20000 Hz/
Ultrasonic waves are safer than x-rays. (T)
All human organs are visible to x-rays. (F) /the liver, the spleen and some other – can be imaged with ultrasonic waves only/
The speed of sound depends on the temperature of the medium. (T)
The distance between adjacent wave fronts equals the wavelength. (T)
Exercise 5. Give your comments on the following statement, speak about advantages/disadvantages; your attitude; history of the invention; the way and prospects of using; being ecological-friendly etc.:
Ultrasonic waves are dangerous.
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Unit 15
ELECTRIC FORCES AND ELECTRIC FIELDS
Exercise 1. Follow the link and watch the video:
https://www.youtube.com/watch?v=mdulzEfQXDE
Exercise 2. Answer the questions:
1.What is Coulomb [‘ku:lɒm] Law good for? (finding the force between small objects, e.g. particles)
2.What does every charged object do? (It generates an electric field that permits space and exert a force on all charged particles.)
3.How does a field carry energy and pass it on the other charged material? (by exerting electric forces)
4.What do electric field lines show? (the magnitude and direction of the force exerted on any nearby positive test charge)
5.What is superposition? (It’s the principle: we have 2 particles that generate their own electric field, we can add the fields together to create a total electric field.)
6.What is the first property of electric field lines? (The field lines must be tangent to the direction of the field of any point.)
7.What is the second property of electric field lines? (The greater the line density, the greater the magnitude of the field.)
8.What is the third property of electric field lines? (The lines always start from positively charged objects and end on negatively charged objects.)
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9.What is the fourth property of electric field lines? (The lines must never cross.)
10.If free charges in a conductive sphere are at electrostatic equilibrium, what is their acceleration equal to? (zero)
Exercise 3. Give examples of using insulators and conductors/semiconductors in everyday life. /electronic devices, electric sockets, electric wires/
Exercise 4. Are the following statements true (T) or false (F)?
If you rub amber it will attract small objects. (T)
Coulomb’s law describes forces between any two stationary charged particles. (T)
Glass, rubber and copper are insulators. (F) /Copper is a conductor/
Objects usually contain equal amount of positive and negative charge. (T)
Electric charge is always conserved. (T)
Exercise 5. Give your comments on the following statement, speak about the way and prospects of using; being ecologicalfriendly etc.:
Electrical fields can be used as water filters. It is a cheap and safe technology.
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Unit 16
ELECTRICAL ENERGY AND CAPACITANCE
Exercise 1. Follow the link and watch the video:
https://www.youtube.com/watch?v=ZrMltpK6iAw
Exercise 2. Answer the questions:
1.Why is it possible to save lives with a defibrillator? (It is a big capacitor: It uses electric charge to store energy, which is then discharged into the patient’s body. The current stops the irregular contractions of the cardiac muscle, and gives the heart a chance to start beating normally.)
2.What does a capacitor consist of? (two parallel conducting plates of opposite charge)
3.What does it allow to do? (A capacitor stores energy.)
4.How can potential energy be used? (to perform work)
5.But how can you determine how much electric potential energy a system has? (A change of potential energy is equal to the work done by the external force or the negative work done by the electric force.)
6.What happens when we place the positive charge between the plates? (The uniform electric field generates a constant force on it /in the direction of the negative plate/.)
7.How can we calculate the work done on the positive plate? (By multiplating the electric force by the distance between the plates. /W=Fd/)
8.What does the electric potential depend on? (on the electric field and the position)
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9.What is called voltage? (the electric potential difference)
10.How can the electric field be found? (The electric field can be found by dividing force by charge or volts per meter.)
Exercise 3. Read the formula: W=Fd /work equals force times the distance/
Exercise 4. Are the following statements true (T) or false (F)?
Connecting to earth can be called zero electric potential.
(T)
Electric potential is electric potential energy per unit charge. (T)
Electric potential is a scalar quantity. (T)
An isolator is a device used to eliminate sparking in automobile ignition systems. (F) /a capacitor/
Ampere is coulomb per volt. (F) /Farad ['færǝd] is coulomb…/
Exercise 5. Give your comments on the following statement, speak about the way and prospects of using; being ecologicalfriendly:
We shouldn’t throw away batteries that cannot be recharged; instead, we should collect them properly and recycle them.
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Unit 17
CURRENT AND RESISTANCE
Exercise 1. Follow the link and watch the video:
https://www.youtube.com/watch?v=HXOok3mfMLM
Exercise 2. Answer the questions:
1.What is electric current? (Electric current is the total amount of charge passing through a wire over a period of time.)
2.How do we get charges to flow from one place to another? (There’s a difference in electric potential between two points. The voltage gives charged particles, electric charge flows from high voltage to low voltage.)
3.How can a constant voltage be created to generate a steady flow of electricity? (Voltaic cell uses chemical reactions to create an electric potential difference between two pieces of different metals, known as electrodes. When the two electrodes are connected, current begins to flow.)
4.What is a ground connected to the wire? (This is just a common conductor that ensures the current always has a path to a large reservoir of charge – usually the Earth itself.)
5.How to measure how strongly the charge flows? (In amperes. One Coulomb of charge passing through the cross section of wire over one second is equal to one ampere of current.)
6.Where does current flow? (Current flows from the positive to the negative terminal.)
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7.What determines how much current flow? (voltage and resistance)
8.What is resistance described in? (Ohms /oum/. One Ohm of resistance would let one Volt of potential generate one Ampere of current.)
9.What is Ohm’s Law about? (When resistance is constant, voltage is directly proportional to current.)
10.How can we calculate voltage? (Current times resistance.)
Exercise 3. Read the formula: V = IR (We can express voltage as current times resistance.)
Exercise 4. Are the following statements true (T) or false (F)?
According to historical convention, the direction of conventional current is the direction positive charges flow.
(T)
When a potential difference is applied between the ends of the conductor, an electric field is set up in the conductor.
(T)
In conductors carrying current the electric potential is continually increasing. (F) /decreasing/
All the materials are ohmic. (F) /There are nonohmic./
In superconductors resistance falls to zero below the critical temperature. (T)
Exercise 5. Give your comments on the following statement, speak about advantages/disadvantages; your attitude; history of the invention; the way and prospects of using; being ecological-friendly etc.:
Superconductors will change our life in the future.
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Unit 18
DIRECT CURRENT CIRCUITS
Exercise 1. Follow the link and watch the video:
https://www.youtube.com/watch?v=g-wjP1otQWI
Exercise 2. Answer the questions:
1.What are the tools you use to build circuits and provide power to the world around us? (Resistors, batteries, and capacitors.)
2.What does a battery do in a circuit? (The battery provides a voltage, generating a current that runs through the whole circuit, lighting up our connected light bulb due to its resistance.)
3.Why is the battery a source of electromotive force? (because it gets charge to move – but it’s not really providing a force, but rather a difference in electrical potential.)
4.Why does the battery get warm while working? (It contains conductive materials that will naturally lose energy as heat.)
5.Why is the actual voltage between the terminals of the battery less than our ideal emf potential? (because there is an internal resistance between the battery’s terminals)
6.How can we find out exactly how much power is lost to the battery’s internal resistance? (You can use the power expression: power equals current times voltage.)
7.What does the principle known as the conservation of charge state? (All current flowing to the junction where the path
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