Physics B Unit 2-7

Wave Application Quick Check. 1. A wave travels at 1,500 m/s with a frequency of 5 hertz. What is its wavelength? 2. Humans can hear thunder at different frequencies. These correspond to wavelengths ranging from 2.75 to 16.5 meters. If the speed of sound is approximately 330 m/s, what frequencies of thunder can humans hear? 3. Two similar waves X and Y travel through the same medium. Wave X has a frequency of 200 hertz and a wavelength of 35 meters. Wave Y has a frequency of 700 hertz. What is the wavelength for wave Y? 4. While traveling in the same medium, sound A has a wavelength of 5 meters, while sound B has a wavelength of 10 meters. Which sound will have a higher pitch? 5. California sea lions communicate underwater at frequencies ranging from 500 to 4,000 hertz. The speed of sound in sea water is approximately 1,500 m/s. What are the approximate wavelengths of sound with which the California sea lions communicate?

1. 300 m 2. 20 to 120 hertz 3. 10 meters 4. sound A, because it has a higher frequency 5. 0.375 to 3 meters

Nature of Light Quick Check. 1. What is the speed of light in a vacuum? 2. The wavelengths of visible light vary from about 300 nm to 700 nm. What is the range of frequencies of visible light in a vacuum? 3. An object absorbs red, orange, yellow, blue, indigo, and violet light. What color is it? 4. Why is a polarized filter helpful to a photographer? 5. What effect do clouds have on the color of the sky?

1. c=3⋅10^8 m/s 2. 4.29⋅10¹⁴ Hz to 1⋅10¹⁵ Hz 3. green 4. It blocks some light but not all. 5. They reflect light waves.

Emission Spectra Quick Check 1. What do the characteristics of electromagnetic radiation include? 2. Which equation correctly relates the energy of electromagnetic radiation to its frequency? 3. What causes electrons in atoms to emit energy after absorbing it? 4. What observation led scientists to postulate the existence of photons?

1. characteristics of both waves and particles 2. E=hv 3. returning to their ground energy states 4. electrons in atoms emitting energy only in certain amounts

States of Matter Quick Check. 1. Which phase change occurs when steam is cooled to 100°C? 2. The amount of energy needed to change a liquid into a gas, without changing its temperature, is known as the __________. 3. In which phase change are hydrogen bonds formed? 4. The specific heat of a substance is 0.215 J/g°C. How much energy is required to raise the temperature of 20 g of the substance from 72°C to 88°C?

1. condensation 2. heat of vaporization 3. freezing 4. 68.8 J

Interference of Waves Quick Check. 1. A wave of amplitude 4.0 meters interferes with a second wave of amplitude 6.0 meters. If both waves are positive, what is the largest amplitude that will result? 2. A taut wire has a wave with a wavelength of 4.5 meters and a frequency of 100 hertz. What is the speed of the wave in the wire? 3. A wave interference where the wave amplitudes combine to yield a lesser amplitude than either of the waves is know as a __________. 4. The position of a standing wave where constructive inference is at maximum is called _________.

1. 10 m 2. 450 m/s 3. Destructive Interference 4. Antinodes

Absorbed Radiation Effects Quick Check 1. Which of these types of EMR is the most harmful? 2. Visible light has a range of wavelengths from about 400-750 nm. Which of these wavelengths is most likely seen as the color red? 3. Radio waves can broadcast signals using two methods. In amplitude modulation (AM), the frequencies of the carrier wave are measured in hundreds of thousands of hertz. For frequency modulation (FM), the frequencies are in hundreds of millions of hertz. Which of these methods uses waves with higher energy? 4. Is exposure to natural radiation on Earth dangerous? 5. Why are dosimeters useful to medical personnel treating a person exposed to acute radiation?

1. visible light 2. 730 nm 3. FM because the frequency is higher. 4. No, because the body repairs damaged cells. 5. They predict the severity of the exposure for treatment.

Electrostatic Force Quick Check. 1. The electrostatic force between two charges is originally FF. Which expression represents the new electrostatic force between the two charges if one charge doubles and the other one is divided by three? 2. Suppose the electrostatic force between two electrons is FF. What is the electrostatic force between an electron and a proton that are the same distance apart? 3. Two charges q1q1 and q2q2 are both negative. Which statement describes the electrostatic force between the two charges? 4. Which statement describes the relationship between the distance between two charges and the electrostatic force between them? 5. What happens to the electrostatic force between two opposite charges of equal magnitude if the negative charge is replaced with a positive charge and the distance between them is halved?

1. 2/3F 2. −F 3. The force is represented as a positive quantity and is repulsive. 4. Electrostatic force is inversely proportional to the square of the distance. 5. The direction of the force changes, and the magnitude of the force quadruples.

Heat Engines and Efficiency Quick Check. 1. A dish of ice cream was left out on a table and is beginning to melt. What conclusions can be made? 2. According to the second law of thermodynamics, the entropy of a system will always __________. 3. What is the only way that entropy can decrease in a system? 4. If a heat engine is operating between two temperatures (QH>QCQH>QC), what is the maximum efficiency attainable?

1. Energy is flowing from the air and the table to the ice cream, which causes the ice cream to melt. 2. stay the same or increase 3. If work is put into the system. 4. 1− Qc/QH

Electric Current and Magnetic Field Quick Check. 1. Which action will cause the induced current to decrease or remain constant? 2. A compass needle moves when it is near a wire with electric current. Which of the following explains this phenomenon? 3. A magnet is moved toward a coil of wire to induce an electric current. What will happen if the magnet is reversed and moved toward the coil of wire again? 4. Which statement describes how the atoms in a conducting wire are organized? 5. Which statement describes the interaction between the north and south poles of two magnets?

1. reversing the polarity of the magnet 2. The electric current creates a magnetic field. 3. The direction of the induced current will change. 4. Positively charged nuclei are packed in an organized pattern, and the negatively charged valence electrons flow freely. 5. The south pole of one magnet attracts the north pole of the other magnet.

Characteristics of Waves Quick Check. 1. Which characteristic is defined as the distance traveled by a wave crest in a given time? 2. How many complete wavelengths are shown in this image? Do not count any partial wavelengths. 3. Which term describes the distance from the crest of a wave to the next crest? 4. Which wave measure is changing by the greatest amount in the image? 5. A surfer talks about riding a 20-foot wave. Which measurement of waves is the surfer describing?

1. speed 2. 3 3. wavelength 4. amplitude 5. amplitude

Kirchhoff's Laws and Circuits Quick Check. 1. A circuit contains two resistors in series. The voltage drop across the first is 10 V. The voltage drop across the second is also 10 V. What is the voltage provided by the power supply in this circuit? 2. What happens to the current in a series circuit as it moves through each component? 3. A 10-volt power supply is placed in series with two 5-ohm resistors. What is the current in the circuit after it passes through each of the two resistors? 4. If the energy of an electric charge flowing in a circuit is conserved, which of the following obeys the Kirchhoff junction rule? 5. What is the ratio of resistances R1:R2?

1. 20 V 2. The current stays the same throughout the circuit. 3. The current will stay the same at 1 amp after passing through both resistors. 4. The sum of the current flowing in is equal to the sum of current flowing out. 5. 1:1

Causal Relationships Quick Check. 1. What is the difference between a causal relationship and a positive correlation? 2. Why is the relationship between voltage and current causal? 3. In this image, the central blue tube represents a wire. Current is flowing through it. What do the pink circles represent? 4. What is the scientific basis of electric generators? 5. You use an adapted bicycle like the one in the picture to generate electrical energy. How would your pedaling rate affect the energy you harvest?

1. Positive correlations indicate a connection between factors but no causality. 2. because voltage creates current 3. the magnetic field generated around the wire 4. the causal relationship between magnetic fields and electric currents 5. The voltage is higher the faster you pedal.

Electric Fields Quick Check. 1. What forces do electric fields represent? 2. What does it mean if electric field lines are close together versus farther apart? 3. What is the force on a 0.0050 C charge in an electric field of 300 V/m? 4. What is the strength of an electric field in which a charged particle of 3.0 × 10−9 C3.0 × 10−9 C is 0.05 m0.05 m from the test charge? 5. What is the value and the direction of an electric field at a distance of 2.5 m from a +1 nC charge?

1. They represent non-contact electrical forces. 2. The strength of the electric field is greater. 3. 1.5 N 4. 1.1 × 10^4 N/C 5. approximately 1.45 V/m directed away from the positive charge

Investigating Currents and Fields Quick Check. 1. As part of an experiment, a student wraps a wire in an electric circuit around an iron core, producing a magnetic field. Which phrase best describes the resulting apparatus? 2. A student used the setup below to investigate electric current and fields. Which action will increase the current in the wire? 3. A student conducts an investigation on electricity and magnetism. The student moves a magnet in and out of a coil of wire. Which relationship will the student discover between the current and the magnetic field strength in a coiled wire? 4. In the experimental setup shown, a coil of wire acts like a bar magnet. Which statement describes how the coil of wire is similar to a bar magnet? 5. A student is conducting an experiment that involves a bar magnet and a coil of wire. What will happen if the bar magnet remains stationary and the coil of wire is moved back and forth within the magnetic field?

1. an electromagnet 2. adding more cells 3. The current increases as the magnet's movement increases. 4. They both have north and south magnetic poles. 5. A current will be induced in the coil of wire.

EM Radiation Energy Transfer Models Quick Check 1. How are the different kinds of electromagnetic radiation described? 2. Which statement regarding energy transmission is true? 3. When deciding which model for electromagnetic radiation to use, which property is most carefully considered? 4. Which question might be asked to determine which model to use to represent electromagnetic radiation? 5. Which application of electromagnetic radiation is an example of energy transfer best modeled as a particle? 6. Which statement best describes how energy transfer occurs during the absorption and emission of electromagnetic radiation by atoms?

1. by their wavelength 2. Wave models work better when energy transmission is continuous. 3. how energy transmission occurs 4. Does the model provide a way to explain observations? 5. spectroscopy 6. The absorption and emission occurs in discrete amounts of energy.

Conductors and Insulators Quick Check. 1. Copper is wrapped with rubber when used in electric wiring. What describes rubber as a material? 2. Which material provides resistance to the flow of electrons? 3. The set up for a science experiment uses a battery, light bulb and copper wire. Which material can be connected to copper wire and a battery to light up the bulb? 4. An electrician wears rubber gloves when working on electrical wiring. What is the purpose of the rubber gloves? 5. Why is metal a good conductor?

1. insulator 2. salt crystals 3. aluminum foil 4. to prevent electric shock by restricting the flow of electrons 5. Its valence electrons flow freely through the material.

Particle-Wave Duality Quick Check 1. The photoelectric effect is good evidence for __________. 2. How can you calculate the momentum of a photon? 3. Interference and diffraction patterns are good evidence for __________. 4. The ultraviolet catastrophe is good evidence for the:

1. the particle nature of EM radiation, because it shows how frequency is proportional to quanta of energy referred to as photons 2. Planck's constant divided by the photon's wavelength 3. the wave nature of EM radiation 4. particle nature of quanta

Atomic Structure Quick Check 1. Which type of subatomic particle is not found in the nucleus? 2. Nearly all the mass of an atom is contained within _____. 3. Which of the following is an elementary particle? 4. A neutron has a neutral charge because:

1. electron 2. the nucleus 3. quark 4. it contains a specific combination of quarks

Wave Characteristics Quick Check. 1. Which type of wave needs a medium to travel? 2. What do both sound and light waves transfer? 3. How does an increase in amplitude affect sound and light waves? 4. What happens to the wavelength when the frequency increases? 5. Which of the following is true about sound waves?

1. sound waves, because they travel by oscillating molecules 2. energy 3. louder sound and brighter light 4. The wavelength decreases. 5. Sound moves faster in the ocean than in the air.

Frequency and Wavelength Quick Check. 1. What is the period of a wave with a wavelength of 8 cm and a frequency of 0.5 hertz? 2. Two ropes are identical. A wave traveling through the first rope has a frequency of 1.5 hertz and a wavelength of 6 meters. What is the frequency of a wave in the second rope if its wavelength is 2 meters? 3. If the wavelength of a wave in a particular medium is tripled, what will happen to the frequency of the wave? 4. If the speed of sound in air is 340 m/s, approximately how long will it take the sound of a clap of thunder to travel 2 kilometers? 5. In music, the note G above middle C has a frequency of about 392 hertz. If the speed of sound in the air is 340 m/s, what is the approximate wavelength of this note?

1. 2 seconds 2. 4.5 hertz 3. It will become one third of its original value. 4. 5.9 seconds 5. 0.87 meters

Radioactivity and Radioactive Decay Quick Check 1. Which of the following transformations is an example of a β−-decay? 2. The unstable uranium nuclide 238 92U 92238U has a half-life of 4.5 billion years and decays into the thorium nuclide 234 90Th 90234Th. The thorium daughter nuclide has a half-life of 24.1 days and decays into the protactinium nuclide 234 91Pa 91234Pa, which has a half-life of 6.75 hours and decays into 234 90U 90234U, whose half-life is 245 thousand years. In a sample of uranium-containing rock, of the four nuclides the most abundant will be __________. 3. The beta minus decay process 13 7N→13 6C+β−+ν¯¯¯ 713N→ 613C+β−+ν¯ is proposed in which nitrogen's proton becomes a neutron. The process is not possible because: 4. The fact that the relative abundance is greater for elements in which the total number of protons and neutrons is a multiple of two is because __________.

1. 31/14Si1 becomes 31/15P because a neutron is converted to a proton. 2. 238 /92U because the very long half-life means a very small rate of decay 3. charge conservation is not satisfied 4. of the four nuclear decay processes only the αα-decay changes the baryon number and does so in increments of four

Mass-Energy Equivalence Quick Check 1. What does the term "c^2" in Einstein's equation mean for conversion between mass and energy? 2. In what form of energy do nuclear power plants harness nuclear energy? 3. Where does nuclear fusion occur naturally? 4. The scientific unit of measurement for energy is the joule (J: kg×m2/s2)(J: kg×m2/s2). If three grams of matter are converted to their equivalent amount of energy, about how much energy is released (use c=3×108 m/s )(use c=3×108 m/s )? 5. The scientific unit of measurement for energy is the joule (J: kg×m2/s2)(J: kg×m2/s2). If 1012 J of energy is produced by the conversion of matter to energy, about how much mass was converted into energy (use c=3×108 m/s)(use c=3×108 m/s)?

1. A small amount of mass can be converted into a large amount of energy. 2. heat 3. in the Sun and other stars 4. 2.7×10^14 J 5. 1.1×10^−5 kg

Wavelength in Different Media Quick Check. 1. The sound of a plucked guitar string travels through the air and strikes the eardrum of a person in the same room. How does the sound wave change when it transfers from the air to the person's eardrum? 2. The table shows the speed of sound in various media. Which list orders the media from shortest wavelength to longest wavelength for sound waves that pass through them? 3. Two different types of rope with different properties are fused together to make one long rope. When a wave transfers from the first type of rope to the second type of rope, the wavelength becomes one-fourth of what it was before the transfer. What is true about the speed of the wave? 4. The table shows the speed of sound in various media. If a sound wave transitions from one medium to another, which transition would result in a shortening of the wavelength of the sound wave? 5. The table shows the speed of ultrasound waves in different tissues in the human body. If an ultrasound wave moves from one tissue to another tissue in the body, which of the following transitions will result in the largest change in the wavelength of the ultrasound wave?

1. Both the speed and the wavelength of the sound change. 2. air, water, glass, steel 3. The speed of the wave becomes one-fourth its original speed after the transfer. 4. steel to water 5. blood to fat

First Law of Thermodynamics Quick Check. 1. Which of the following statements regarding heat is accurate? 2. What is the correct unit for heat? 3. What happens when a cold piece of metal is placed in hot water? 4. How do the molecules differ in a cup of hot water and a cup of cold water?

1. Heat is a form of energy. 2. joules 3. heat will flow from the water to the metal 4. In the hot water, the molecules are moving faster than in the cold water.

Physics B Semester Exam 1. Object A has a temperature of 3 T. It comes in contact with Object B, which has a temperature of 2 T. Which of the following is true? 2. The total amount of energy released when 45 g of 175°C steam is cooled to 90°C is __________.Reminder: As steam is condensed it will turn into water at 100 ° C100 ° C. 3. What is the efficiency of the heat engine if the input is 260 J and the useful output is 124.8 J? 4. What is true about semiconductors? 5. Where is the electric field between a charged balloon and a charged piece of paper 0.04 m away? 6. Use the image to answer the question. 12v on top R1 to the right R2 on bottom. 7. Select the correct answer from the list. 8. A student uses the experimental setup shown to study electricity and magnetism. She moves the magnet in and out of the coiled wire. Which conclusion can the student make from the experiment? 9. Which experiments lead to understanding the causal relationship between magnetic fields and electric current? 10. A sound has a higher pitch than a bell. Which quantity must also be higher in this sound than in the bell? 11. A submarine sends a sonar wave toward the bottom of the ocean. The frequency of the wave is 2.50 megahertz (2.50×106 hertz) and the speed is 1,200 meters/second. The echo from the ocean floor is detected 10.0 seconds later. How far is the ocean floor from the submarine? 12. What happens to sound waves from an object as it moves toward you? 13. The speed of a sound wave depends on __________. 14. Which statement regarding sound traveling in air is correct? 15. What is true about light? A. Light travels in a straight line.B. Light travels in elliptical paths.C. The speed of light in a vacuum is 2 ⋅108 m/s2 ⋅108 m/s.D. The speed of light is a vacuum is 3 ⋅108 m/s3 ⋅108 m/s. 16. Why does grass appear green? 17. Which statement about the effect of temperature on the speed of sound is correct? 18. Do the quanta that make up matter behave like waves? 19. The image shows hydrogen's emission and absorption spectrum. This is compatible with which kind of model? 20. How much energy is contained in particle with a mass of m=1×10^−9 kg? 21. Why are all atoms in their natural state electrically neutral? 22. In a β−-decay __________. 23. When galaxies move toward Earth, the frequency of the light received from Earth appears increased in frequency. If a galaxy is moving away, the light appears to have lower frequencies. If the spectral lines in the hydrogen spectrum above appear shifted to the right when viewing a distant galaxy, what direction is the galaxy moving relative to Earth? 24. What determines the severity of the effects of radiation on the human body?

1. Heat will flow from Object A to Object B. 2. 110,601 J 3. 48% 4. You can change how easily electrons move through them. 5. The electric field is all around the balloon and paper including between them, where, depending on their charge, there would be a force of either attraction or repulsion. 6. resistence all the way down is 1, 2, xxxx. potential difference is 4, 8, 12. current is 4, 4, 4 all the way down. 7. As charges move in a closed loop, they gain as much energy as they lose 8. A changing magnetic field produces an electric current. 9. discovering that a moving magnet generated a current in a conductor and proving that the magnitude of the current depended on the number of coils in the conductor 10. frequency 11. 6 km 12. The pitch gets higher because of an increase in frequency. 13. the density of the medium 14. The frequency of a sound does not affect the speed at which it travels. 15. A and D 16. Grass absorbs all light except for green, which it reflects. 17. As temperature increases, the speed of sound increases because molecules in the medium collide more frequently. 18. Yes, in certain situations, just like all particles. 19. particle model because the atom's electron absorbs and emits energy in discrete wavelengths. 20. 9×10^7 J 21. The number of electrons is equal to the number of protons. 22. the daughter nuclide has one more proton and one less neutron than the parent nuclide 23. Away from Earth. 24. time and amount of exposure

Thermodynamics Unit Test. 1. Two objects are placed touching each other. Object A has a temperature of 1 T and Object B has a temperature of 2 T. What will be true after some time has passed? 2. What is true of heat and temperature? 3. 1,000 J of energy are needed to melt 10 g of a solid substance that is already at its melting point. What is the heat of fusion of the substance? 4. The amount of energy needed to change 25 g of −30°C−30°C ice into 0°C liquid water is __________. 5. Why is it impossible for a heat engine to be 100% efficient? 6. An inventor is applying for a patent. He claims his new heat engine can produce 1,200 J of work for every 1,800 J of heat applied to it. In 3-5 sentences, evaluate this claim after solving for η.

1. Heat will flow from Object B to Object A. 2. Heat flows due to a temperature difference between two objects. 3. 100 J/g 4. 9,887.5 J 5. Some heat is always lost to the environment. 6. The work is 1200j. The heat is 1800j. Divide the 2 and you get 0.67. So the inventor claims to have developed an engine that takes in 1800j of heat and produces 1200j so his claim is valid. Put #6 in your own words.

Reflection and Refraction Quick Check. 1. What does the image of an object look like through a convex lens when the object is further from the lens than the focal point? 2. What happens when light rays reflect? 3. Based on how it refracts light, what would you expect images formed by a concave lens to look like? 4. What happens to light rays when they enter a different medium?

1. It is upside down and smaller than the object. 2. They bounce back. 3. Magnified 4. They bend.

Waves Unit Test 1. What is one way that light waves differ from sound waves? 2. Which best explains why high frequency electromagnetic waves are more likely to cause harm to living things? 3. How do the frequencies and the speeds of yellow light and blue light compare? 4. Which phrase correctly defines the amplitude of a wave? 5. As waves move through water, the water at any point rises and falls. At a given moment, two points along the wave's line of travel that are 2 meters apart have each risen to form adjacent crests. Which measure is described by this observation? 6. A sound wave passes through regions of the ocean with varying density. How do the varying wavelengths correspond to the density of the water? Select the two correct answers. 7. The speed of a wave is 2m/s, and its wavelength 0.4 meters. What is the period of the wave? 8. Two similar waves are traveling through the same medium. Wave A has a frequency that is 3 times that of wave B. How do their wavelengths compare? 9. The lowest frequency that we can hear is about 20 hertz. If the speed of sound in air is 340 meters/second, what is the wavelength of that low sound? 10. A stationary source produces a sound wave at a frequency of 100 Hz. The wave travels at 1125 feet per second. A car is moving toward the sound source at a speed of 200 feet per second. What is the wavelength of the stationary sound source and the wavelength that a person in the car perceives? 11. When the string on a violin vibrates, waves move in both directions along the string, interfering with each other. Sometimes these waves interact to make nodes and antinodes. What are these kinds of waves called? 12. Owls communicate using long-wavelength hoots, while songbirds use short-wavelength tweets. Which of the sounds can be heard over a greater distance in a forest? 13. The number of wavelengths that pass a point each second is called __________. 14. The table below shows the speed of sound in water at different temperatures and salinities. Which statement can be inferred about the speed of sound in freshwater and in seawater? 15. Consider the following list of properties. Which applies to light?A: Mechanical waveB: Electromagnetic waveC: Travels in circular pathsD: Travels in a straight line 16. Which of the following statements about light is true? 17. How many polarized filters are needed minimally to block light intensity? 18. Which color of light has the most energy and why? 19. In what way is an image formed by a mirror inverted? 20. The table shows the speed of ultrasound waves in different tissues in the human body. 21. If a wave transfers from one medium to another medium with different properties, which statement is true? 22. You are fishing in a boat anchored in a bay. You notice that the current is in the eastern direction with small wave crests that are 15 meters apart, and they are gently rocking the boat once every 5 seconds. You decide to lift the anchor and begin trolling slowly to the west at 2.0 meters/second. In 1-2 sentences, explain the strategy for calculating how often the wave crests will rock the boat in this situation based on your investigation. 23. Suppose you were stranded on a desert island with only a convex lens and a mirror. Describe how you could use each of these tools to signal for help.

1. Light waves do not require a medium to propagate. 2. As a wave's frequency increases, more energy is carried by the wave in a given time period. 3. The frequency of blue light is greater than that of yellow light, while the speeds of both colors of light are the same. 4. the vertical distance from the crest or trough of a wave to the equilibrium 5. wavelength 6. Shorter wavelengths correspond to lesser density of the water./ Longer wavelengths correspond to greater density of the water. 7. 0.2 seconds 8. λA=1/3λB 9. 17 m 10. wavelength of the stationary source: 11.25 ft; perceived wavelength: 9.25 ft 11. standing waves 12. hoot of the owl 13. frequency 14. The speed of sound increases as the density of water increases. 15. B and D 16. The speed of light in a vacuum is 3⋅10^8 m/s 17. two filters perpendicular to each other 18. Violet light has the most energy because it has the highest frequency. 19. From front to back 20. The wavelength of the wave increases. 21. The frequency remains constant. 22. v=fwave f=frequency of current 1/5 Hz wave=wavelength which is 15m v=(1/5)times 15 v= 3 m/s 3m/s minus 2 m/s = 1 m/s so 1 m/s This is good but not complete. You need to keep going to find the new frequency. Take your new velocity you found and put it back into the same equation with the same wavelength of 15 m to find the new frequency. 23. well you can use it two ways. one way is to collect wood for a fire and use the mirror and lens to light the fire, make it a bonfire that's big and will attract other people to help you. The second way is to use the lens and mirror to shine at an airplane or if a satellite goes by you can try shining it at that or a boat which will attract attention

Ohmic Device Resistance Quick Check. 1. How do you find the total resistance, Rtotal, for a series circuit with resistances R1, R2, and R3? 2. Which statement correctly describes the resistivity of a wire? 3. Which representation shows the relationship between resistance and the length of a wire? 4. The table shows the resistivity of four different materials. About how many times greater is the resistance of a tungsten wire than the resistance of a silver wire of the same length and cross-sectional area? 5. The resistance of a wire is 8 Ω8. What would the resistance be if the length of the wire was increased by a factor of four? 6. What current is produced with a voltage of 6.0 V and a resistance of 445 ohms?

1. Rtotal = R1 + R2 + R3 2. Resistivity depends on the material the wire is made from and has units of ohm-meters. 3. R∝L 4. 3.52 5. 32 Ω 6. 13.5 mA

Electricity and Circuits Unit Test. 1. A balloon is rubbed against a sweater. Which of the following describes the result of this interaction? 2. A positive charge is 1 m to the left of a negative charge. The positive charge is then moved and placed 1 m to the right of the negative charge. What happens to the electrostatic force between the charges? 3. Two equal charges of magnitude q are at a distance of r units apart. In which scenario will the electrostatic force between them remain the same? 4. When would force lines connect two charges? 5. What is the force on a 0.0020 C charge in an electric field of 150 V/m? 6. A circuit is constructed with a 20.0-V power supply and two resistors in series: R1 = 4.00 ohms, and R2 = 2.00 ohms. What is the resulting current in the circuit? 7. What is the resistance of resistor R1? 8. Find the total resistance and the current through resistor 2. 9. Find the potential difference across R2 and the current through R2. 10. A 15-volt power supply is used to power a circuit with two resistors in series. The voltage drop across R1 is 5 volts. What is the voltage drop across R2? 11. A 10-volt power supply is used to power a circuit, producing a current of 2 A. If the total resistance of the circuit is doubled, how will this affect the circuit? 12. A series circuit is formed with a 10-V power supply and two resistors, where R1 = 6 ohms and R2 = 4 ohms. The current through the resistors is I1 and I2, respectively. What are the values of I1 and I2? 13. Identify the electrical properties of materials that are highly conductive and those that are used in insulation. Use one or two sentences to complete your answer. 14. Given a 10-V power supply, would a 20-ohm resistor and a 5-ohm resistor need to be arranged in parallel or in series to generate a current of 2.5 A? How much current would move through each resistor? In 3-4 sentences, answer each question and explain your answers. 15. In one to two sentences, explain the importance of applying Kirchhoff's Junction Rule in circuit design. 16. Applying Kirchhoff's Junction Rule, what happens to the power source and current when the parallel circuit has two branches, each with a resistor, R? In one to two sentences, answer the question and explain your reasoning.

1. The fibers of the sweater lose electrons. 2. The electrostatic force remains attractive, and the magnitude does not change. 3. when q is doubled and r is doubled 4. if the charges were opposite 5. 0.30 N 6. 3.33 A 7. 7.5 Ω 8. Total Resistance = 1.5 ohms. Current through R2 = 8 A. 9. Potential Difference = 2 V. Current = 6 A. 10. 10 volts 11. The current will change so that the voltage drop for a complete loop through the circuit remains at 10 V. 12. I1 = I2 = 1.0 A 13. normally these are metal materials that have the electrons move through and around the material. The materials used for insulation have the atoms bound tightly together and are paired with electrons holding them together and unable to move to another atom. 14. the resistors need to be parallel to "generate a current of 2.5A." there would also be different currents across each resistor which they are individuals. "the 5-ohm resistor" that would have a 2 A and with the 20-ohm resistor that would have a .5A. the resistance would be 40 ohms to be able to "generate a current of 2.5 A." 15. the Kirchhoff's junction rule describes the variation of a voltage and the flow of a current through circuits which is why it is important to apply the Kirchhoff's junction rule in a circuit design. 16. the current will be split between both the branches attached to the parallel circuit but the voltage will stay the same through the circuit. #13-16 put in your own words please.

Electricity and Magnetism Unit Test. 1. A current is induced by moving a magnet in and out of a coil of wire. What will happen to the induced current if you move the magnet twice as fast? 2. A student connects a battery to a light bulb using wires, creating a closed simple circuit. The student connects an ammeter to the circuit and places a compass next to the wires. The student then decides to connect a second battery to the circuit. Which statement describes the changes that will occur after connecting the second battery? 3. A student is comparing a step-up transformer with a step-down transformer. Which data should she collect from each device? 4. What happens to a copper wire when it is moved across a magnetic field?

1. The induced current will increase. 2. The ammeter will detect an increase in current, and the compass will detect a stronger magnetic field. 3. the ratio of incoming and outgoing voltages 4. Voltage and electric current are induced.

Series and Parallel Circuits Quick Check. 1. A 6 ohm, 5 ohm, and 8 ohm resistor are connected in series with a 30 V battery. What is the total resistance and the current through the 8 ohm resistor? 2. A 6 ohm, 5 ohm, and 8 ohm resistor are connected in parallel with a 30 V battery. What is the total resistance and the current through the 8 ohm resistor? 3. Complete the chart for this circuit: 4. Complete the chart for this circuit: 5. Imagine a string of holiday lights, with many bulbs connected to each other by wires. One bulb burns out, causing the bulbs next on the string not to work either. What type of circuit must the holiday lights be using?

1. Total Resistance = 19 ohms. Current = 1.58 A. 2. Total Resistance = 2.03 ohms. Current = 3.75 A. 3. R1= 2.5, 10, 4 R2= 2, 10, 5 R3= 5, 10, 2 Battery= xxxx, 10, 11 4. R1 = 4, 20, 5 R2= 2, 10, 5 R3= 1.2, 6, 5 Battery= xxxxx, 36, 5 5. series

The Photoelectric Effect Quick Check 1. Which item best illustrates the behavior of an electron in the photoelectric effect? 2. How does the photoelectric effect support the particle model of electromagnetic radiation? 3. Which statement explains how the photoelectric effect influenced the way physicists view electromagnetic radiation? 4. Which statement describes photons? 5. Why was the wave model of electromagnetic radiation unsuitable for describing the photoelectric effect? 6. Which photoelectric effect observation supports the idea that the energy of a photon is proportional to its frequency?

1. a funnel because it can capture energy if the energy level is greater than the opening in the bottom 2. When high energy radiation shines on a material, electrons are freed from the material's atoms, behaving like particles. 3. Physicists initially considered electromagnetic radiation using the wave model. The photoelectric effect brought about the particle model. 4. Photons behave like particles of electromagnetic radiation. 5. because it predicted that electrons would be able to store energy 6. Electrons only have enough energy to escape the material when the light's frequency is above a certain level.

Measurable Effects of Electromagnetism Quick Check. 1. A student is moving a magnet through a coil of wire. Which of these indicates the strength of the electric current in the coil? 2. Which factors should be modified to change the amount of current induced in the wire? 3. A transformer is being built to triple the voltage produced. Which data are collected to investigate whether the transformer can achieve the goal? 4. A student is moving a length of wire in a magnetic field. The wire is connected to an ammeter. In her investigation, she finds that some types of motion do not generate an electric current. Which of these motions results in no electric current? 5. Suppose that you want to build a transformer that will convert 70 V power coming in the primary coil to 245 V power going out of the secondary coil. What is the smallest total number of turns (primary turns plus secondary turns) you need to create the transformer?

1. changes in the magnetic field of the magnet 2. the number of loops in the coil and the strength of the permanent magnet 3. the ratio of the number of turns in the primary and secondary coils 4. moving the wire parallel to the magnetic field 5. 9

Sound Wave Phenomena Quick Check. 1. A person moves away from a stationary sound source. Which phrase describes the sound perceived by the person? 2. Which image corresponds to what moment in time? 3. A stationary source produces a sound wave at a frequency of 100 Hz. The wave travels at 1125 feet per second. A car is moving toward the sound source at a speed of 100 feet per second. What is the wavelength of the stationary sound source and the wavelength that a person in the car perceives? 4. When a guitar string is plucked, what part of the standing wave is found at the fixed ends of the string? 5. A person is singing in the shower. They notice that as certain notes become very loud, the shower walls vibrate. Which statement describes this effect?

1. lower pitch and longer wavelength 2. The low-pitched sound corresponds to the sound source moving away; its wavelength is longer. The high-pitched sound corresponds to the sound source getting closer; its wavelength is shorter. 3. wavelength of the stationary source: 11.25 ft; perceived wavelength: 10.25 ft 4. the nodes 5. The note is one of the harmonic resonance for the shower.

Quantum Theory and Particle Physics Unit Test 1. Which of the following gives good evidence for the particle nature of EM radiation? 2. Which of the following gives good evidence for the wave nature of EM radiation? 3. When studying the photoelectric effect, which parameters did scientists think were relevant for electrons to be released or not in both the wave and particle models? 4. The image represents the gaps between allowed energy levels for electrons. Which model best describes this phenomenon? 5. Which subatomic particle has the smallest mass? 6. The atomic number on the periodic table refers to the number of _____ within an atom. 7. Considering that an up quark has a charge of +2/3 and a down quark has charge of −1/3 which of the following represents the correct quark combination for a proton? 8. If an atom gives off electromagnetic radiation with a frequency of 2.0×10^15s−1, what is the radiation's energy? 9. A nuclide of phosphorus 30/15P decays into a nuclide of silicon 30/14Si. In order to satisfy charge conservation and lepton number conservation the other products must be __________. 10. In a gamma decay process __________. 11. Nuclide XX has a higher rate of decay than nuclide YY. Based on this information, which of the following statements must be true? 12. A microwave has a typical wavelength of about 0.1 meter. What is the comparable wavelength of a radio wave? 13. A satellite phone can be used to place a call from virtually anywhere in the world. What type of wave does the satellite phone likely transmit to the satellite orbiting above Earth? 14. The speed of a light wave cc is related to its wavelength λλ and its frequency ff by c=λfc=λf. If the speed of light is 3×1083×108 meters/second and the wavelength of an infrared wave used in a remote control is 7×10−97×10−9 meters, then what is its frequency? 15. In what way does a lead apron protect human cells from X-rays? 16. Why are children more susceptible to the effects of ionizing radiation? 17. Which statement is correct about the half-lives of radioactive elements? 18. Source A has a half-life of 10 million years, and source B has a half-life of 5 million years. After 10 million years, what percent of each source remains? 19. The probability that a randomly chosen nucleus in a radioactive sample will have decayed in a given time is 96.875%. How many half-lives has the sample experienced? 20. A radioactive sample starts with 800,000 undecayed nuclei. After 12 hours, 700,000 of the nuclei have decayed. What is the half-life of the sample? 21. How did the development of electrical signals sent through wires change communication? 22. In three to four sentences, explain how the photoelectric effect supports a particle model of electromagnetic radiation. As part of your response, evaluate the idea that radiation frequency and intensity highlight how the wave model is inadequate to explain the photoelectric effect. 23. In one to two sentences, explain why electromagnetic radiation can be modeled as both a wave and a particle. 24. Explain how the conservation of energy and the conservation of matter might still be considered true when put together in spite of the ability of each to convert into the other. 25. In 1-2 sentences, explain why the emission spectra of elements show lines of different colors but only in narrow bands. 26. The half-life of radium-226 is 1,600 years and the half-life of carbon-14 is 5,730 years. In one to sentences, mathematically prove that the decay constant for radium-226 is larger than the decay constant for carbon-14.

1. photoelectric effect 2. interference patterns 3. frequency and intensity for the wave model; frequency only for the particle model 4. the particle model because the arrows represent discrete particle-like jumps 5. electron 6. protons or electrons 7. 2 up, 1 down 8. 1.3×10^−18 J 9. a positron and an antineutrino 10. a parent nuclide was in an excited state 11. Nuclide Y has a larger half-life than nuclide X. 12. Greater than 0.1 meter. 13. radio wave 14. 4×10^16 Hz 15. The lead apron shields cells from exposure. 16. They have many growing cells that can easily have DNA damaged. 17. The half-lives of radioactive elements vary from fractions of a second to billions of years. 18. 50% of source A and 25% of source B 19. 5 20. 4 hours 21. Signals could be sent anywhere a wire could reach and no longer were restricted to line of sight. 22. Electromagnetic radiation is light. So the photoelectric effect supports a particle model of electromagnetic radiation is when a EM radiation reflects against some material such as metal for example. This causes the electrons that are in the metal material absorb the energy that the radiation is giving. Then the electrons use this energy as a way to break away from the atoms they're attached to. When you shine a light on metal none of the electrons the metal contains wont be released when the light has a frequency lower than the energy that binds the electron. The electron would be thrown off the metal if the intensity of the light was strong or the force from above the electrons density would knock off it. How do these things support a particle model of light? 23. Because electromagnetic radiation sometimes acts like both a wave and a particle. This happens because a wave transfers from one place to another place. It could be a wave because radio waves carry information through the air from one place to another place, but it could also act like a particle as when electrons that are free in a conductor and charged particles travel through the space or it could also happen in the change of energy. 24. Matter and energy can not be destroyed nor created when they change from one form to another form but if you consider them together as a single entity they can be conserved. 25. Well electrons and atoms can only give a certain amount of energy as they change from one energy level to a different energy level and each energy level has a specific frequency and each frequency that is electromagnetic radiation shows a different color in the spectrum at each frequency change. 26. I got this wrong so you have to figure this one out on your own. PUT THESE IN YOUR OWN WORDS PLEASE AND THANK YOU!

The Speed of Sound Quick Check. 1. In general, sound is conducted fastest through __________. 2. Which statement correctly compares the speed of sound in solids and gases? 3. The table below shows the speed of sound in water at different temperatures and salinities. Based on the table, which statement describes the relationship between temperature and the speed of sound in water? 4. A student conducts an experiment in which sound waves pass through air and then through water. Which statement describes the wave speed as it passes from air to water? 5. The speed of sound in different media at increasing temperatures is shown in the data table below. Why does sound travel the slowest in air?

1. solids 2. The speed of sound is generally faster in solids than in gases, because solids are denser than gases. 3. Sound travels faster in warmer water, both in fresh water and sea water. 4. The speed of sound increases. 5. The distance between molecules of air is greater than for molecules of water.

Radioactive Decay Quick Check 1. In the equation N=N0e−λtN=N0e−λt, which symbol represents the decay constant of the radioactive material? 2. Which term is defined as the amount of time it takes for 50% of a sample of radioactive nuclei to decay? 3. At the start of an experiment, there are 120,000 undecayed radioactive nuclei in a sample. After 8 hours, there are 7,500 undecayed nuclei in the sample. What is the half-life of the sample? 4. What is the half-life of a radioactive sample that is 75% decayed after 142.8 days? 5. What happens when people are administered iodine-131?

1. λ 2. half-life 3. 2 hours 4. 71.4 days 5. It behaves like any other nonradioactive iodine isotope in the body, but it can be tracked by doctors.