The figure shows the arrangement of two point charges. Testing of weapons samples and their destruction refers to ______ hazard factors
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A1 The graph shows the dependence of the speed of a rectilinearly moving body on time. Determine the acceleration modulus of the body.
1) 5 m/s 2
2) 10 m/s 2
3) 15 m/s 2
4) 12.5 m/s 2
A2 A crane lifts a load with constant acceleration. A force equal to 8 * 10 3 H acts on the load from the side of the cable. The force acting on the cable from the side of the load
1) is equal to 8 * 10 3 N and is directed downward
2) less than 8 * 10 3 N and directed downwards
3) more than 8 * 10 3 N and directed upwards
4) is equal to 8 * 10 3 N and is directed upwards
A3 A stone of mass 200 g is thrown at an angle of 45° to the horizon with an initial velocity v = 15 m/s. The modulus of gravity acting on the stone at the time of the throw is equal to
1) 0
2) 1.33 N
3) 3.0 N
4) 2.0 N
A4 The balls move at the speeds shown in the figure and stick together when they collide. What will be the momentum of the balls after the collision?
A5 To destroy the barrier, a massive ball is often used, swinging on the boom of a crane (see figure). What energy transformations occur when the ball moves from position A to position B?
1) the kinetic energy of the ball is converted into its potential energy
2) the potential energy of the ball is converted into its kinetic energy
3) the internal energy of the ball is converted into its kinetic energy
4) the potential energy of the ball is completely converted into its internal energy
A6 The figure shows the profile of a traveling wave at some point in time. The phase difference of oscillations of points 1 and 3 is equal to
1) 2π
2) pi
3) π/4
4) π/2
A7 Under a microscope, the chaotic movement of the smallest particles of chalk in a drop of vegetable oil is observed. This phenomenon is called
1) diffusion of liquids
2) evaporation of liquids
3) convection in liquid
4) Brownian motion
A8 The figure shows a graph of a cyclic process carried out with an ideal gas. The mass of the gas is constant. Isothermal compression corresponds to the section
1) AB
2) Sun
3) CD
4) DA
A9 A vessel with a movable piston contains water and its saturated steam. The volume of steam isothermally reduced by 2 times. The concentration of vapor molecules in this case
1) has not changed
2) increased by 2 times
3) decreased by 2 times
4) increased by 4 times
A10 The graph shows the dependence of the pressure of a monatomic ideal gas on its volume. During the transition from state 1 to state 2, the gas did work equal to 5 kJ. The amount of heat received by the gas during this transition is equal to
1) 1 kJ
2) 4 kJ
3) 5 kJ
4) 7 kJ
A11 The figure shows the location of two fixed point electric charges + q and - q (q > 0). The direction of the total tension vector electric field these charges at point A corresponds to the arrow
1) 1
2) 2
3) 3
4) 4
A12 A current I flows through a conductor with resistance R. How will the amount of heat released in the conductor per unit time change if its resistance is increased by 2 times, and the current strength is reduced by 2 times?
1) will increase by 2 times
2) will decrease by 2 times
3) will not change
4) decrease by 8 times
A13 The magnetic field is created at point A by two parallel long conductors with currents I1 and I2, located perpendicular to the plane of the drawing. The vectors and at point A are directed in the plane of the drawing as follows:
1) - up, - down
2) - up, - up
3) - down, - up
4) - down, - down
A14 The figure shows voltage oscillograms on two different elements of an AC electrical circuit.
The fluctuations of these voltages have
1) the same periods, but different amplitudes
2) different periods and different amplitudes
3) different periods, but the same amplitudes
4) the same periods and the same amplitudes
A15 The figure shows an experiment on the refraction of light. Using the table below, determine the refractive index of the substance.
|
injection a |
20° |
40° |
50° |
70° |
|
sin a |
1) 1,22
2) 1,47
3) 1,88
4) 2,29
A16 The addition of coherent waves in space, in which a time-constant spatial distribution of the amplitudes of the resulting oscillations is formed, is called
1) interference
2) polarization
3) dispersion
4) refraction
A17 The wavelength of red light is almost 2 times that of violet light. Red light photon energy relative to violet light photon energy
1) 4 times more
2) more than 2 times
3) 4 times less
4) less than 2 times
A18 The arsenic nucleus 67 33 As consists of
1) 33 neutrons and 34 protons
2) 33 protons and 34 neutrons
3) 33 protons and 67 neutrons
4) 67 protons and 34 electrons
A19 The sample contains 2 * 10 10 nuclei of the radioactive cesium isotope 137 55 Cs, which has a half-life of 26 years. After how many years will 0.25 * 10 10 nuclei of a given isotope remain undecayed?
1) 26 years old
2) 52 years old
3) 78 years old
4) 104 years old
A20 An ideal gas in the amount of ν moles at temperature T and pressure p occupies a volume V. What constant can be determined from these data?
1) Avogadro number N A
2) gas constant R
3) Planck's constant h
4) Boltzmann constant k
A21
Taking into account the measurement errors (ΔR = ±1 Ohm, ΔU = ± 0.2 V), find the expected voltage at the ends of the AB circuit section at R2 = 50 Ohm.
1) 3.5V
2) 4 V
3) 4.5V
4) 5.5V
A21 The graph shows the results of measuring the voltage at the ends of section AB of a DC circuit consisting of two resistors connected in series, at various values of the resistance of the resistor R2 and a constant current strength I (see figure).
Single State exam in Physics, 2008
demo version
Part A
A1. The figure shows the schedule of the bus from point A to point B and back. Point A is at the point x= 0, and point B - at the point x= 30 km. What is the maximum speed of the bus for the whole round trip?
| 1) | 40 km/h |
| 2) | 50 km/h |
| 3) | 60 km/h |
| 4) | 75 km/h |
Solution. It can be seen from the graph that the bus traveled from point A to point B at a constant speed, and from point B to point A - at a constant speed. The maximum speed of the bus is 60 km/h.
Correct answer: 3.
A2. An ice floe floating in a glass of fresh water transferred to a glass of salt water. In this case, the Archimedean force acting on the ice
Solution. For floating bodies, the Archimedean force acting on them is equal to the force of gravity. Since the gravity of the ice floe has not changed, the Archimedean force has not changed either.
Correct answer: 4.
A3. The figure shows conditional images of the Earth and the Moon, as well as the vector of the force of attraction of the Moon by the Earth. It is known that the mass of the Earth is about 81 times the mass of the Moon. Which arrow (1 or 2) is directed along and what is the modulus of the force acting on the Earth from the side of the Moon?
Solution. According to Newton's third law, the action force is equal and opposite to the reaction force. The force acting on the Earth from the side of the Moon is directed along 2 and is equal to .
Correct answer: 2.
A4. The body moves uniformly along the plane. The pressure force of the body on the plane is 20 N, the friction force is 5 N. The coefficient of sliding friction is
| 1) | 0,8 |
| 2) | 0,25 |
| 3) | 0,75 |
| 4) | 0,2 |
Solution. The coefficient of friction relates the body pressure force on the plane and the friction force:
Correct answer: 2.
A5. When performing laboratory work, the student set an inclined plane at an angle of 60 ° to the table surface. The length of the plane is 0.6 m. What is the moment of gravity of a bar with a mass of 0.1 kg relative to the point O when it passes through the middle of an inclined plane?
| 1) | 0.15 Nm |
| 2) | 0.30 Nm |
| 3) | 0.45 Nm |
| 4) | 0.60 Nm |
Solution. The angle between the direction of gravity and the inclined plane is 30°. The moment of gravity is
Correct answer: 1.
A6. Balls of the same mass move as shown in the figure and collide absolutely inelastically. What will be the momentum of the balls after the collision?
Solution. Oscillation period mathematical pendulum equals
Increasing the length of the pendulum by 4 times increases the period by 2 times. The weight of the load does not affect the period.
Correct answer: 1.
A8. After the push, the block slides up the inclined plane. In the reference system associated with the plane, the direction of the axis is 0 x shown in the left figure. Which of the figures correctly shows the directions of the vectors of the bar's velocity, its acceleration and the resultant force?
| 1) |
 | 2) |
 |
| 3) |
 | 4) |
 |
Solution. As the block slides up, its velocity is aligned with the 0 axis x. According to Newton's second law, the acceleration of a body is directed towards the resultant force. Only picture 1 is suitable.
Correct answer: 1.
A9. A plasticine ball with a mass of 0.1 kg has a speed of 1 m/s. It hits a stationary trolley with a mass of 0.1 kg, attached to a spring, and sticks to the trolley (see figure). What is the total mechanical energy of the system during its further vibrations? Ignore friction.
| 1) | 0.1 J |
| 2) | 0.5 J |
| 3) | 0.05 J |
| 4) | 0.025 J |
Solution. According to the law of conservation of momentum, the speed of a trolley with a sticky plasticine ball is
Correct answer: 4.
A10. The constant mass of an ideal gas is involved in the process shown in the figure. The highest gas pressure in the process is reached
| 1) | at point 1 |
| 2) | at point 3 |
| 3) | on the entire segment 1–2 |
| 4) | on the entire segment 2–3 |
Solution. Let's draw isobar lines on the graph passing through points 1, 2 and 3 (see Fig.). In coordinates T–V the greater the angle of the isobar line, the greater the pressure. Thus, the highest gas pressure is in state 1.
Correct answer: 1.
A11. The photo shows two thermometers used to determine the relative humidity of the air. Below is a psychrometric table in which humidity is indicated as a percentage.
| t dry term. | Difference between dry and wet thermometer readings | ||||||||
| °C | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 15 | 100 | 90 | 80 | 71 | 61 | 52 | 44 | 36 | 27 |
| 16 | 100 | 90 | 81 | 71 | 62 | 54 | 45 | 37 | 30 |
| 17 | 100 | 90 | 81 | 72 | 64 | 55 | 47 | 39 | 32 |
| 18 | 100 | 91 | 82 | 73 | 64 | 56 | 48 | 41 | 34 |
| 19 | 100 | 91 | 82 | 74 | 65 | 58 | 50 | 43 | 35 |
| 20 | 100 | 91 | 83 | 74 | 66 | 59 | 51 | 44 | 37 |
| 21 | 100 | 91 | 83 | 75 | 67 | 60 | 52 | 46 | 39 |
| 22 | 100 | 92 | 83 | 76 | 68 | 61 | 54 | 47 | 40 |
| 23 | 100 | 92 | 84 | 76 | 69 | 61 | 55 | 48 | 42 |
| 24 | 100 | 92 | 84 | 77 | 69 | 62 | 56 | 49 | 43 |
| 25 | 100 | 92 | 84 | 77 | 70 | 63 | 57 | 50 | 44 |
The relative humidity of the air in the room in which the shooting was carried out is equal to
Solution. According to the Boyle-Mariotte law, in an isothermal process, pressure is inversely proportional to volume. When the volume is increased by 4 times, the pressure decreases by 4 times.
Correct answer: 4.
A13. The figure shows a dependency graph absolute temperature T mass of water m from time t in the implementation of heat removal with a constant power P.
At the point in time t= 0 the water was in a gaseous state. Which of the following expressions determines the specific heat capacity of ice based on the results of this experiment?
| 1) | |
| 2) | |
| 3) | |
| 4) |
Solution. On the graph, the sections of the broken line correspond to the following processes (from left to right): cooling of water vapor, condensation of steam into water, cooling of water, crystallization of water into ice, cooling of ice. The heat capacity of ice can be determined from the last section of the graph as the ratio of heat taken to the mass and change in temperature of the ice. The heat absorbed is equal to the product of power and time. As a result, we get:
Correct answer: 4.
A14. A monatomic ideal gas in an amount of 4 moles absorbs an amount of heat of 2 kJ. In this case, the gas temperature rises by 20 K. The work done by the gas in this process is equal to
| 1) | 0.5 kJ |
| 2) | 1.0 kJ |
| 3) | 1.5 kJ |
| 4) | 2.0 kJ |
Solution. According to the first law of thermodynamics
Correct answer: 2.
A15. The heat engine has an efficiency of 25%. The average power of heat transfer to the refrigerator during its operation is 3 kW. How much heat is received by the working body of the machine from the heater in 10 s?
| 1) | 0.4 J |
| 2) | 40 J |
| 3) | 400 J |
| 4) | 40 kJ |
Solution. For 10 s, the heat engine gives off heat to the refrigerator. The heat received from the heater and the heat given off to the refrigerator are related by the relation:
Correct answer: 4.
A16. How will the strength of the electrostatic interaction of two electric charges change when they are transferred from vacuum to a medium with a permittivity of 81, if the distance between them remains the same?
Solution. The strength of the electrostatic interaction of two point electric charges is inversely proportional to the dielectric constant of the medium. The permittivity of vacuum is equal to 1. When charges are transferred to a medium with a permittivity of 81, the force of their interaction will decrease by a factor of 81.
Correct answer: 2.
A17. The figure shows the location of two fixed point electric charges +2 q and - q. The module of the electric field strength vector of these charges has
Solution. Denote the distance between charges 2 a. Let us calculate the modules of the electric field strength vectors of these charges at the points A, B and C:
,
,
.
It can be seen that the maximum value was obtained at the point B.
Correct answer: 2.
A18. In the section of the circuit shown in the figure, the resistance of each of the resistors is 2 ohms. The total resistance of the section is
| 1) | 8 ohm |
| 2) | 6 ohm |
| 3) | 5 ohm |
| 4) | 4 ohm |
Solution. The resistance of two resistors connected in parallel is
.
The total resistance is .
Correct answer: 3.
A19. The figure shows a graph of the dependence of the current in an incandescent lamp on the voltage at its terminals. At a voltage of 30 V, the current power in the lamp is
| 1) | 135 W |
| 2) | 67.5W |
| 3) | 45 W |
| 4) | 20 W |
Solution. The graph shows that at a voltage of 30 V, the current strength is 1.5 A. The current power is .
Correct answer: 3.
A20. Compare the inductance and two coils, if at the same current strength the energy magnetic field, created by current in the first coil, 9 times greater than the energy of the magnetic field created by the current in the second coil.
| 1) | 9 times more than |
| 2) | 9 times less than |
| 3) | 3 times more than |
| 4) | 3 times less than |
Solution. For the same current strength, the energy of the magnetic field in the coil is directly proportional to its inductance. Since the energy of the magnetic field of the first coil is 9 times greater, then its inductance is 9 times greater than the second.
Correct answer: 1.
A21. Among the examples given electromagnetic waves has the maximum wavelength
Solution. The maximum wavelength among the given examples is the radiation of the antenna of the radio transmitter.
Correct answer: 4.
A22. Which of the images 1-4 serves as an image of the object AB in a thin lens with a focal length F?
| 1) | 1 |
| 2) | 2 |
| 3) | 3 |
| 4) | 4 |
Solution. A converging lens gives a real inverted image of objects that are at a distance greater than the focal length.
Correct answer: 2.
A23. Two initially resting electrons are accelerated in an electric field: the first in a field with a potential difference U, second - 2 U. The accelerated electrons fall into a uniform magnetic field, the lines of induction of which are perpendicular to the speed of the electrons. The ratio of the radii of curvature of the trajectories of the first and second electrons in a magnetic field is
| 1) | |
| 2) | |
| 3) | |
| 4) |
Solution. The radius of curvature of the trajectories is directly proportional to the momentum of the particle. The acquired momentum, in turn, is directly proportional to the square root of the potential difference. Since the potential difference for the first electron is 1/2 of the potential difference for the second electron, the ratio of the radii of curvature of the trajectories of the first and second electrons is .
Correct answer: 3.
A24. The sine of the limiting angle of total internal reflection at the glass-air interface is 8/13. What is the speed of light in glass?
| 1) |
 |
| 2) |
 |
| 3) |
 |
| 4) |
 |
Solution. Let us denote the limiting angle of total internal reflection as α. According to the law of refraction
Correct answer: 3.
A25. One scientist checks the patterns of oscillation of a spring pendulum in a laboratory on Earth, and another scientist in a laboratory on Earth. spaceship flying away from stars and planets with the engine off. If the pendulums are the same, then in both laboratories these patterns will be
Solution. According to the postulate of the special theory of relativity, everything physical phenomena proceed in the same way in all inertial frames of reference. The laboratory on Earth and the spacecraft can be considered as inertial frames of reference. The patterns will be the same at any speed of the ship.
Correct answer: 1.
A26. The figure shows the diagrams of four atoms. Black dots represent electrons. What is the diagram for an atom?
| 1) |
 | 2) |
 | 3) |
 | 4) |
 |
Solution. The number of electrons in a neutral atom coincides with the number of protons, which is written at the bottom before the name of the element. There are 5 electrons in an atom.
Correct answer: 3.
A27. What fraction of a large number of radioactive atoms remains undecayed after a time interval equal to two half-lives?
| 1) | 25 % |
| 2) | 50 % |
| 3) | 75 % |
| 4) | 0 % |
Solution. According to the law of radioactive decay
Correct answer: 1.
A28. Through a series of radioactive decays, uranium is converted to lead. How many α- and β-decays does he experience in this case?
| 1) | 8α and 6β |
| 2) | 6α and 8β |
| 3) | 10α and 5β |
| 4) | 5α and 10β |
Solution. During α-decay, the mass of the nucleus decreases by 4 amu. e. m., and during β-decay, the mass does not change. In a series of decays, the mass of the nucleus decreased by 238 – 206 = 32 AU. e. m. For such a decrease in mass, 8 α-decays are required.
Correct answer: 1.
A29. In experiments on the photoelectric effect, they took a metal plate with a work function 
and began to illuminate it with the light of frequency. Then the frequency was reduced by a factor of 2, while simultaneously increasing by a factor of 1.5 the number of photons incident on the plate in 1 s. As a result, the number of photoelectrons leaving the plate in 1 s
Solution. With a decrease in the frequency of the incident light by a factor of 2, the photon energy, equal to , becomes less than the work function. The photoelectric effect will cease to be observed, the number of photoelectrons leaving the plate will become equal to zero.
Correct answer: 2.
A30. The graph shows the results of measuring the length of the spring at various values of the weight of the weights lying in the cup of the spring balance.
Taking into account measurement errors (, 
) spring stiffness k approximately equal to
| 1) | 7 N/m |
| 2) | 10 N/m |
| 3) | 20 N/m |
| 4) | 30 N/m |
Solution. Let's draw a straight line through the points of the graph (see Fig.).
It can be seen that in the absence of a load ( m= 0 d) the length of the spring is . The stiffness of a spring is equal to the ratio of the force acting on the spring to the amount of deformation:
Correct answer: 3.
Part B
IN 1. A flat air capacitor was disconnected from the current source, and then the distance between its plates was increased. What will happen in this case with the charge on the capacitor plates, the electric capacitance of the capacitor and the voltage on its plates?
For each position of the first column, select the corresponding position of the second and write down the selected numbers in the table under the corresponding letters.
| A | B | V |
Transfer the resulting sequence of numbers to the answer sheet (without spaces).
Solution. According to the law of conservation, the charge on the plates of the capacitor will not change. The capacitance of a capacitor is inversely proportional to the distance between the plates. As the distance between them increases, the electrical capacity decreases. A voltage equal to the ratio of charge to electric capacity, on the contrary, will increase.
Answer: 321.
IN 2. A load weighing 2 kg, fixed on a spring with a stiffness of 200 N/m, performs harmonic oscillations. The maximum acceleration of the load is equal to . What is the maximum load speed?
Solution. Load acceleration maximum at maximum operating force, which occurs in the extreme positions of tension or compression of the spring. At this moment, the speed of the load is zero, and the total energy is equal to the potential energy of the deformed spring:
.
The maximum speed of the load at the moment of passing the equilibrium position. At this moment, the total energy is equal to the kinetic energy of the load:
AT 3. The cylinder contains 20 kg of nitrogen at a temperature of 300 K and a pressure of . What is the volume of the balloon? Round your answer to the nearest integer.
Solution. Using the Mendeleev-Clapeyron equation, we get:
AT 4. Straight conductor length l\u003d 0.2 m, through which current flows I= 2 A, located in a uniform magnetic field with induction V= 0.6 T and is located perpendicular to the vector. What is the modulus of the force acting on the conductor from the magnetic field?
Solution. The power of the ampere is .
Answer: 0.24.
Part C
C1. A piece of plasticine collides with a bar sliding towards the horizontal surface of the table and sticks to it. The velocities of plasticine and the bar before impact are opposite and equal to and . The mass of the bar is 4 times the mass of plasticine. The coefficient of sliding friction between the bar and the table is μ = 0.17. How far will sticky blocks with plasticine move by the moment when their speed decreases by 30%?
Solution. Denote the mass of plasticine m, then the mass of the bar is 4 m. Using the law of conservation of momentum, we determine the speed of the block with plasticine after the collision:
The weight of the block with plasticine on a horizontal surface is , and the friction force acting on the block is . Using the law of conservation of energy, we determine the desired distance:
Answer: 0.15 m.
C2. 10 mol of a monatomic ideal gas was first cooled by reducing the pressure by a factor of 3, and then heated to an initial temperature of 300 K (see Fig.). How much heat was received by the gas in section 2−3?
Solution. Since the pressure decreased by a factor of 3 during isochoric cooling, the temperature also decreased by a factor of 3 and amounted to . In section 2–3, the gas pressure remains constant. The heat capacity of an ideal monatomic gas in an isobaric process is . The amount of heat transferred to the gas in section 2–3 is equal to
Answer: 41550 J.
C3. To a current source with EMF ε = 9 V and internal resistance r= 1 ohm connected in parallel connected resistor with resistance R\u003d 8 Ohm and a flat capacitor, the distance between the plates of which d\u003d 0.002 m. What is the electric field strength between the capacitor plates?
Solution. The strength of the electric current in the circuit is 
. The potential difference between the resistor terminals is . The same potential difference will be between the capacitor plates. The electric field strength between the capacitor plates is
Answer: 4 kV/m.
C4. An inflatable raft 4 m wide and 6 m long floats on the surface of the water. The sky is overcast with a continuous cloud cover that completely scatters sunlight. Determine the depth of the shadow under the raft. Ignore the depth of the raft and the scattering of light by water. The refractive index of water relative to air is taken equal to 4/3.
Solution. We denote the width of the plot , the limiting angle of total internal reflection α (see Fig.). The depth of the shadow is . According to the law of refraction of light:
.
We get
.
Answer: 1.76 m.
C5. Let's assume the schema energy levels atoms of some substance has the form shown in the figure, and the atoms are in a state with energy . An electron colliding with one of these atoms bounced off, acquiring some additional energy. The momentum of an electron after a collision with a resting atom turned out to be equal to . Determine the kinetic energy of the electron before the collision. The possibility of emission of light by an atom in a collision with an electron is neglected.
Solution. Let us denote the energy of the electron before the collision W. The energy of the electron has increased, which means that the energy of the atom has decreased. An atom could only pass from a state with energy to a state with energy . Using the law of conservation of energy, we obtain:
Answer: 
.
technogenic
ecological
socio-economic
Solution:
The testing of weapons and their destruction are military hazards. Military factors - factors caused by the work of the military industry. For example, the transportation of military materials and equipment, the operation of military installations and the entire complex of military means in the event of hostilities.
4. Danger, always associated with a specific threat of human impact, is called ...
real
potential
realized
natural
Solution:
The danger, always associated with a specific threat of human impact, is called real. It is coordinated in space and time. For example, a tank truck moving along a highway with the inscription “Flammable” is a real danger to a person who is near the highway. As soon as the tank truck leaves the area where a person is located, it will immediately turn into a source of potential danger in relation to this person. real danger along with potential and realized hazards, they are distinguished by the degree of completeness of the impact of the hazard on the objects of protection.
5. The figure shows the location of the homosphere (G) and noxosphere (H), characterizing …
conditionally safe situation
dangerous situation
safe situation
Solution:
The figure shows the location of the homosphere (H) and noxosphere (H), characterizing a conditionally safe situation. A conditionally safe situation occurs when a person is in the noxosphere, but uses personal protective equipment to neutralize the danger or is in specially equipped shelters inside the noxosphere (observation cabins, control posts, stationary or portable rest rooms, etc.).
6. With the appropriate location of the homosphere (G) and noxosphere (N), a dangerous situation is realized, which is shown in the figure ...
Solution:
With the appropriate location of the homosphere (G) and noxosphere (N), a dangerous situation is realized, which is shown in Figure 3. A dangerous situation occurs when the homosphere (the space in which a person is in the process of the activity under consideration) completely coincides with the noxosphere (the space in which there are constantly or occasional hazards). Hazards can be realized in the form of injury or illness. The combination of homosphere and noxosphere is unacceptable.
7. The figure shows the location of the homosphere (G) and noxosphere (H), characterizing ...
situation of short-term danger
safe situation
conditionally safe situation
dangerous situation
Solution:
The figure shows the location of the homosphere (H) and noxosphere (H), characterizing the situation of short-term danger. The situation of short-term or local danger arises when there is a partial coincidence of the homosphere (the space in which a person is in the process of the activity under consideration) and the noxosphere (the space in which dangers constantly exist or periodically arise).
8. An event consisting in a violation of the operable state of an object is called ...
defect
damage
Solution:
An event consisting in violation of the healthy state of an object is called a failure. If the performance of an object is characterized by a set of values of some technical parameters, then a sign of a failure is the output of the value of any of these parameters beyond the limits of tolerances. In addition, the failure criteria may also include qualitative signs indicating a violation of the normal operation of the facility.
10. Hazards caused by climatic and natural phenomena are called …
natural
anthropogenic
technogenic
social
Solution:
Hazards caused by climatic and natural phenomena are called natural. They arise when weather conditions and natural light in the biosphere change, as well as from natural phenomena occurring in the biosphere (floods, earthquakes, etc.). Natural hazard, along with anthropogenic and man-made hazards, is distinguished by the nature of its origin.
12. Dangers resulting from erroneous or unauthorized actions of a person or group of people are called ...
anthropogenic
natural
technogenic
permanent
Solution:
Hazards arising from erroneous or unauthorized actions of a person or a group of people are called anthropogenic. And the higher the transformative activity of a person, the higher the level and number of anthropogenic hazards - harmful and dangerous factors that negatively affect a person and his environment. Anthropogenic hazard, along with natural and man-made hazards, is distinguished by the nature of origin.
13. The property of an object to perform and save in time the functions assigned to it in the specified modes and conditions of use, Maintenance, repairs, storage and transportation is called ...
reliability
reliability
durability
maintainability
Solution:
The property of an object to perform and maintain in time the functions assigned to it in the given modes and conditions of use, maintenance, repairs, storage and transportation is called reliability. Reliability is an internal property of an object. It manifests itself in the interaction of this object with other objects inside technical system, as well as with the external environment, which is an object with which the technical system itself interacts in accordance with its purpose. This property determines the efficiency of the technical system functioning in time through its indicators. Being a complex property, the reliability of an object (depending on its purpose and operating conditions) is evaluated through indicators of particular properties - reliability, durability, maintainability and safety - individually or in a certain combination.
USE 2008: physics. Part 1 Demo version of the exam 2008 in Physics. Part 1 (A1-A30).
The figure shows the schedule of the bus from point A to point B and back. Point A is at point x = 0, and point B is at point x = 30 km. What is the maximum speed of the bus for the whole round trip?
1) 40 km/h 2) 50 km/h 3) 60 km/h 4) 75 km/h
An ice floe floating in a glass of fresh water was transferred to a glass of salt water. In this case, the Archimedean force acting on the ice
1) decreased, since the density of fresh water is less than the density of salt water 2) decreased, since the depth of immersion of the ice in water decreased 3) increased, since the density of salt water is higher than the density of fresh water 4) did not change, since the buoyancy force is equal to weight ice floes in the air
The figure shows conditional images of the Earth and the Moon, as well as the vector FΠ of the force of attraction of the Moon by the Earth. It is known that the mass of the Earth is about 81 times the mass of the Moon. Which arrow (1 or 2) is directed along and what is the modulus of the force acting on the Earth from the side of the Moon?
1) along 1, equal to FΠ 2) along 2, equal to FΠ 3) along 1, equal to 81FΠ 4) along 2, equal to FΠ/81
The body moves uniformly along the plane. The pressure force of the body on the plane is 20 N, the friction force is 5 N. The coefficient of sliding friction is
1) 0,8 2) 0,25 3) 0,75 4) 0,2
When performing laboratory work, the student set an inclined plane at an angle of 60 ° to the table surface. The length of the plane is 0.6 m. What is the moment of gravity of a bar with a mass of 0.1 kg relative to the point O when it passes through the middle of the inclined plane?
1) 0.15 Nm 2) 0.30 Nm 3) 0.45 Nm 4) 0.60 Nm
Balls of the same mass move as shown in the figure and collide absolutely inelastically. What will be the momentum of the balls after the collision?
If both the length of the mathematical pendulum and the mass of its load are increased by 4 times, then the period of free harmonic oscillations of the pendulum
1) will increase by 2 times 2) will increase by 4 times 3) will decrease by 4 times 4) will decrease by 2 times
After the push, the block slides up the inclined plane. In the reference system associated with the plane, the direction of the 0x axis is shown in the left figure. Which of the figures correctly shows the directions of the vectors of the bar's velocity, its acceleration a and the resultant force F?
A plasticine ball with a mass of 0.1 kg has a speed of 1 m/s. It hits a stationary trolley with a mass of 0.1 kg attached to a spring and sticks to the trolley (see figure). What is the total mechanical energy of the system during its further vibrations? Ignore friction.
1) 0.1 J 2) 0.5 J 3) 0.05 J 4) 0.025 J
The constant mass of an ideal gas is involved in the process shown in the figure. The highest gas pressure in the process is reached
1) at point 1 2) at point 3 3) on the entire segment 1–2 4) on the entire segment 2–3
The photo shows two thermometers used to determine the relative humidity of the air. Below is a psychometric chart that lists humidity as a percentage.
Psychometric table
1) 37% 2) 40% 3) 48% 4) 59%
At constant temperature the volume of a given mass of ideal gas has increased by 4 times. At the same time, the gas pressure
1) increased by 2 times 2) increased by 4 times 3) decreased by 2 times 4) decreased by 4 times
The figure shows a graph of the dependence of the absolute temperature T of water of mass m on time t during heat removal with a constant power P. At time t = 0, water was in a gaseous state. Which of the following expressions determines the specific heat capacity of ice based on the results of this experiment?
A monatomic ideal gas in an amount of 4 moles absorbs an amount of heat of 2 kJ. In this case, the gas temperature rises by 20 K. The work done by the gas in this process is equal to
1) 0.5 kJ 2) 1.0 kJ 3) 1.5 kJ 4) 2.0 kJ
The heat engine has an efficiency of 25%. The average power of heat transfer to the refrigerator during its operation is 3 kW. How much heat is received by the working body of the machine from the heater in 10 s?
1) 0.4 J 2) 40 J 3) 400 J 4) 40 kJ
How will the strength of the electrostatic interaction of two electric charges change when they are transferred from vacuum to a medium with a permittivity of 81, if the distance between them remains the same?
1) increase 81 times 2) decrease 81 times 3) increase 9 times 4) decrease 9 times
The figure shows the location of two fixed point electric charges +2q and -q.
The modulus of the electric field strength vector of these charges has
1) maximum value at point A 2) maximum value at point B 3) identical values at points A and C 4) identical values at all three points
In the section of the circuit shown in the figure, the resistance of each of the resistors is 2 ohms. The total resistance of the section is
1) 8 ohm 2) 6 ohm 3) 5 ohm 4) 4 ohm
The figure shows a graph of the dependence of the current in an incandescent lamp on the voltage at its terminals. At a voltage of 30 V, the current power in the lamp is
1) 135 W 2) 67.5 W 3) 45 W 4) 20 W
Compare the inductances L1 and L2 of two coils if, at the same current strength, the energy of the magnetic field created by the current in the first coil is 9 times greater than the energy of the magnetic field created by the current in the second coil.
1) L1 is 9 times larger than L2 2) L1 is 9 times smaller than L2 3) L1 is 3 times larger than L2 4) L1 is 3 times smaller than L2
Among the given examples of electromagnetic waves, the maximum wavelength has
1) infrared radiation of the Sun 2) ultraviolet radiation of the Sun 3) radiation of a γ-radioactive preparation 4) radiation of a radio transmitter antenna
Which of the images 1 - 4 serves as an image of the object AB in a thin lens with a focal length F?
1) 1 2) 2 3) 3 4) 4
Two initially resting electrons are accelerated in an electric field: the first in a field with a potential difference U, the second - 2U. The accelerated electrons fall into a uniform magnetic field, the lines of induction of which are perpendicular to the speed of the electrons. The ratio of the radii of curvature of the trajectories of the first and second electrons in a magnetic field is
1) 1/4 2) 1/21 3) √2/2 4) √2
The sine of the limiting angle of total internal reflection at the glass-air interface is 8/13. What is the speed of light in glass?
1) 4.88 10 8 m/s 2) 2.35 10 8 m/s 3) 1.85 10 8 m/s 4) 3.82 10 8 m/s
One scientist tests the oscillation patterns of a spring pendulum in a laboratory on Earth, and another scientist in a laboratory on a spaceship flying away from stars and planets with the engine off. If the pendulums are the same, then in both laboratories these patterns will be
1) the same at any speed of the ship 2) different, since time flows more slowly on the ship 3) the same only if the ship’s speed is low 4) the same or different depending on the module and direction of the ship’s speed
The figure shows the diagrams of four atoms. Black dots indicate electrons. What scheme corresponds to atom 13B?
What fraction of a large number of radioactive atoms remains undecayed after a time interval equal to two half-lives?
1) 25% 2) 50% 3)75% 4) 0%
As a result of a series of radioactive decays, uranium 238/92U turns into lead 206/82Pb. How many α- and β-decays does he experience in this case?
1) 8 α and 6 β 2) 6 α and 8 β 3) 10 α and 5 β 4) 5 α and 10 β
In experiments on the photoelectric effect, they took a metal plate with a work function of 3.4 10-19 J and began to illuminate it with light with a frequency of 6 1014 Hz. Then the frequency was reduced by a factor of 2, while simultaneously increasing by a factor of 1.5 the number of photons incident on the plate in 1 s. As a result, the number of photoelectrons leaving the plate in 1 s
1) increased by 1.5 times 2) became equal to zero 3) decreased by 2 times 4) decreased by more than 2 times
The graph shows the results of measuring the length of the spring at various values of the weight of the weights lying in the cup of the spring balance (figure on the right).
Taking into account the measurement errors (Δm = ±1 g, Δl = ± 0.2 cm), the spring constant k is approximately equal to
1) 7 N/m 2) 10 N/m 3) 20 N/m 4) 30 N/m
