Physical Science Final Exam Review Flashcards

ELECTROSTATICS

1. The two rules of electric charge are:

   • Like charges repel each other, and unlike charges attract.

   • Charge is conserved; the total charge in an isolated system remains constant.

2. The three major particles that make up an atom are:

   • Protons (found in the nucleus)

   • Neutrons (found in the nucleus)

   • Electrons (found in electron clouds around the nucleus).

3. An atom with more electrons is called an anion. An atom with more protons is called a cation.

4. Three ways to charge an object are:

   • Conduction (transfer of charge by direct contact)

   • Induction (charging without direct contact)

   • Friction (transfer of electrons when two materials rub against each other).

5. (Drawing Description)

   • Positive charge: Field lines radiate outward from the charge.

   • Negative charge: Field lines point inward toward the charge.

6. A conductor allows electrons to flow freely (e.g., metals), while an insulator does not allow electron flow (e.g., rubber, glass).

7. Coulomb’s Law states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them:
      $F = k \frac{|q_1 q_2|}{r^2}$
      Where:

   • $F$ = force between charges

   • $k$ = Coulomb's constant

   • $q_1$ and $q_2$ = magnitudes of the charges

   • $r$ = distance between the centers of the charges.

8. Electricity is a flow of charge, while gravity is a force of attraction between masses. They are similar because both can exert forces over a distance and follow an inverse-square law.

9. The constant "k" in Coulomb’s Law signifies the strength of the electric force; a higher value of k indicates a stronger attraction or repulsion between charges.

10. If an atom has partial positive and negative charges but still remains neutral, it is called a polar molecule. For a water molecule (H₂O):

    • Oxygen has a partial negative charge, and hydrogens have partial positive charges due to unequal sharing of electrons.

    • (Drawing Description)
      

      • Draw a bent diagram indicating the oxygen atom with a negative delta (δ-) and hydrogen atoms with positive deltas (δ+).

11. Changes in electric force between two charged metal spheres:

    • If the charge on both spheres is doubled (force increases by a factor of 4 due to $F \propto q_1 q_2$).

    • If the charges remain the same but the distance is tripled (force decreases to 1/9 due to $F \propto \frac{1}{r^2}$).

    • If the charges are both doubled and the distance is doubled (force increases by a factor of 2).

    • If the charges remain the same but the spheres get 5 times closer (force increases by a factor of 25).

OHMS LAW AND CIRCUITS

12. What is measured with the ampere?
       The ampere measures electric current, representing the flow of electric charge.

13. What is also called an electrical potential? What is it measured in?
       Voltage is also called electrical potential, and it is measured in volts (V).

14. What is measured in Ω?
       Resistance is measured in ohms (Ω).

15. True or False. Voltage flows through a circuit. Explain.
       False. Voltage is not a flow; it is the potential difference that causes current to flow through a circuit.

16. What links current, voltage and resistance? What is the equation for this relationship? What does each symbol stand for?
       Ohm’s Law links current (I), voltage (V), and resistance (R). The equation is: $V = I \times R$, where:

    • $V$ = voltage (volts)

    • $I$ = current (amperes)

    • $R$ = resistance (ohms)

17. True or False. You will receive a lethal shock if you are freely hanging off the ground from a 10,000 volt power line. Explain.
       True, if you are grounded or in contact with the ground while being exposed to a high voltage power line, a lethal shock can occur due to the potential difference creating a current flow through your body.

18. What would happen if you touched a ladder and the 10,000 volt power line? Explain.
       You would likely receive a severe electric shock or fatal injury, as touching the ladder while in contact with the power line creates a path for current to flow through your body.

19. Explain the difference between ac and dc. What devices typically produce ac and dc respectively?
       AC (alternating current) periodically reverses direction, commonly produced by power plants for household electricity. DC (direct current) flows in one direction, typically produced by batteries and electronic devices.

20. True or False. A current-carrying wire is electrically charged? Explain.
       False. While current-carrying wires have moving charges (electrons), the wire itself remains neutral as the number of positive charges (ions) is balanced with the negative charges (electrons).

21. True or False. The electric company delivers many electrons to your house each year. Explain.
       True, but more accurately, the company provides the potential difference (voltage) that allows electrons to flow in your electrical system when a circuit is completed.

22. What is measured in kilowatt-hours? What else could it also be measured in?
       Energy consumption is measured in kilowatt-hours (kWh), and it can also be measured in joules (J).

23. What is the equation for electric power? What does each symbol stand for?
       The equation for electric power is: $P = V \times I$, where:

    • $P$ = power (watts)

    • $V$ = voltage (volts)

    • $I$ = current (amperes)

24. Explain the difference in how current is used between series and parallel circuits?
       In series circuits, current is the same through all components, while in parallel circuits, current can vary across different branches depending on their resistance.

25. As the number of branches in a parallel circuit increases, what happens to the resistance? To the current?
    
       As the number of branches increases, the total resistance decreases because additional paths for current flow are created, leading to an increase in total current supplied by the power source.

MAGNETISM

26. What is the rule that defines the attraction and repulsion of magnets?

    • Like poles repel each other, and unlike poles attract.

27. What is the source of all magnetism?

    • The source of all magnetism is the motion of electric charges, specifically, the movement of electrons in atoms.

28. True or False. If you cut a magnet in half you will have a monopole magnet? Explain.

    • False. If you cut a magnet in half, you will create two smaller magnets, each with a north and south pole; monopole magnets do not exist.

29. What is a naturally occurring permanent magnet called?

    • A naturally occurring permanent magnet is called a lodestone.

30. What is the region surrounding a magnet? What is used to represent these regions?

    • The region surrounding a magnet is called the magnetic field. Magnetic field lines are used to represent these regions.

31. If moving electrons induce a magnetic field in a permanent magnet, why don’t all atoms behave as magnets?

    • Not all atoms behave as magnets because their electron spins may cancel each other out, resulting in no net magnetic moment.

32. In what way does a magnetic field surround a current-carrying wire?

    • A magnetic field surrounds a current-carrying wire in concentric circles, with the direction determined by the right-hand rule.

33. Explain how you can make an electromagnet. What would make it stronger?

    • You can make an electromagnet by wrapping a wire coil around a ferromagnetic core and passing an electric current through it. Increasing the number of coils or the current will make it stronger.

34. What is the difference between a motor and a generator?

    • A motor converts electrical energy into mechanical energy, while a generator converts mechanical energy into electrical energy.

35. Whose law summarizes electromagnetic induction? Summarize his law.

    • Faraday's law summarizes electromagnetic induction, stating that a changing magnetic field within a loop induces an electromotive force (EMF) in the loop.

36. Who else contributed to this law?

    • Joseph Henry also contributed to the understanding of electromagnetic induction, particularly in self-induction and mutual induction.

37. How can you get more voltage using electromagnetic induction?

    • You can get more voltage by increasing the strength of the magnetic field, increasing the rate of change of the magnetic field, or increasing the number of loops in the coil.

38. Explain the relationship between electric and magnetic fields.

    • Electric and magnetic fields are interrelated aspects of electromagnetism; a changing electric field generates a magnetic field, and a changing magnetic field generates an electric field, as described by Maxwell's equations.

VIBRATION AND WAVES

39. What is simple harmonic motion? Provide an example of simple harmonic motion.    Simple harmonic motion is a type of periodic motion where the restoring force is directly proportional to the displacement from the equilibrium position. An example of simple harmonic motion is a mass on a spring or a pendulum swinging back and forth.

40. What is the relationship between frequency and period?    The frequency (f) is the number of cycles per second, measured in hertz (Hz), while the period (T) is the time taken for one complete cycle, measured in seconds. They are inversely related: $f = \frac{1}{T}$ and $T = \frac{1}{f}$.

41. What happens to waves if the medium it is traveling in changes in any way?    If the medium changes (density, elasticity, etc.), the speed of the wave changes, which can affect its wavelength and frequency.

42. You shake the end of a slinky back and forth 25 times in 10 seconds. What is the frequency and period?    Frequency (f) = Number of shakes / Time = $\frac{25 \text{ shakes}}{10 \text{ seconds}} = 2.5 \text{ Hz}$.    Period (T) = 1 / Frequency = $\frac{1}{2.5 \text{ Hz}} = 0.4 \text{ seconds}$.

43. True or False. A wave can carry energy from place to place without displacing any matter. Explain.    True. A wave can transport energy through a medium without physically displacing matter in a permanent way, as the particles of the medium oscillate around their equilibrium positions.

44. How does a transverse wave differ from a longitudinal wave? Draw and label a transverse wave and longitudinal wave.    A transverse wave has oscillations perpendicular to the direction of wave travel (e.g., light waves), while a longitudinal wave has oscillations parallel to the direction of wave travel (e.g., sound waves). (Drawing Description: Draw a transverse wave with crest and trough labels, and a longitudinal wave with compression and rarefaction labels).

45. What does λ stand for?    λ (lambda) stands for wavelength, which is the distance between successive crests or troughs of a wave.

46. True or False. All waves require a medium. Explain.    False. Electromagnetic waves, like light waves, do not require a medium to propagate; they can travel through a vacuum.

47. What is the relationship between frequency, wavelength and wave speed?    Wave speed (v) is equal to the frequency (f) multiplied by the wavelength (λ): $v = f \times \lambda$.

48. What is a standing wave?    A standing wave is a wave that remains in a constant position, formed by the interference of two waves traveling in opposite directions, resulting in points of no displacement (nodes) and points of maximum displacement (antinodes).

49. Draw a harmonic series for the first 4 harmonics.    (Drawing Description: Illustrate the first four harmonics, demonstrating the different standing wave patterns.)

SOUND AND LIGHT

50. True or False. Sound is a transverse wave. Explain.    Sound is a longitudinal wave, not a transverse wave, because the oscillations of particles in the medium occur parallel to the direction of wave travel.

51. True or False. The speed of sound is the same in all media. Explain.    False. The speed of sound varies depending on the medium (solid, liquid, or gas) and its properties, such as temperature and density. Sound travels fastest in solids and slowest in gases.

52. Explain the difference between a mechanical wave and an electromagnetic wave.    Mechanical waves require a medium to travel through (e.g., sound waves), while electromagnetic waves do not require a medium and can travel through a vacuum (e.g., light waves).

53. What is the difference between a high and low pitch?    Pitch is determined by the frequency of the sound wave; high pitch corresponds to higher frequency waves, while low pitch corresponds to lower frequency waves.

54. What function of a wave makes music louder?    Amplitude is the function of a wave that makes music louder; higher amplitude results in louder sound.

55. What is the range of hearing for humans? What are the frequencies less than this called? What are the frequencies greater than this called?    The range of hearing for humans is approximately 20 Hz to 20,000 Hz (20 kHz). Frequencies less than 20 Hz are called infrasound, and frequencies greater than 20 kHz are called ultrasound.

56. The reflection of sound? The multiple reflections of sound that produce a garbled noise?    The reflection of sound is called an echo. Multiple reflections of sound that produce a garbled noise are known as reverberation.

57. The study of sound properties?    The study of sound properties is called acoustics.

58. What is natural frequency?    Natural frequency is the frequency at which an object vibrates when it is disturbed from its equilibrium position and then allowed to vibrate freely.

59. How does resonance occur?    Resonance occurs when an object is forced to vibrate at its natural frequency, often leading to an increase in amplitude of the waves.

60. You see a flash of lightning and hear the rumble of thunder 8 seconds later. How far away was the lightning bolt?    Sound travels at approximately 343 meters per second (in air). Therefore, if thunder is heard 8 seconds later, the lightning bolt was about $343 \times 8 = 2744$ meters away.

61. Explain what makes a machine louder when it is running on a factory floor.    A machine can sound louder due to its mechanical vibrations being transmitted through the floor and building structures, creating a greater amplitude of sound waves.

62. Explain what wave property you need when tuning your radio allows you to hear your favorite radio station.    You need to adjust the frequency of the radio wave to match the frequency of the station's broadcast for clear reception.

63. Two waves that are in phase undergo what type of interference?    Two waves that are in phase undergo constructive interference, resulting in increased amplitude.

64. Explain how noise-cancelling headphones work.    Noise-cancelling headphones work by using microphones to pick up external sound waves and generating sound waves that are opposite (180 degrees out of phase) to the incoming noise, canceling it out through destructive interference.

65. What is a beat?    A beat is an interference pattern created when two sound waves of slightly different frequencies interfere with one another, resulting in a periodic variation in loudness.

66. A car is moving toward you blowing its horn. Explain how the sound of the horn changes as it gets closer. What happens to the sound of the horn as the car passes you and moves away? What is this phenomenon called?    As the car approaches, the sound of the horn has a higher pitch (frequency), known as a blue shift. After the car passes, the pitch lowers (red shift) as it moves away. This phenomenon is called the Doppler effect.

67. What is the difference between a red and blue shift?    A red shift indicates that an object is moving away from the observer, resulting in longer wavelengths, while a blue shift indicates that an object is moving toward the observer, resulting in shorter wavelengths.

68. What is the difference between a bow wave and a shock wave?    A bow wave is created when an object moves through a medium faster than the waves it produces, forming a V-shaped pattern, while a shock wave is a type of wave created when an object exceeds the speed of sound in a medium, leading to a sudden change in pressure.

69. Draw the wave patterns for the following situations: v less than vw, v equals vw, v exceeds vw.    (Drawing Description: Illustrate the wave patterns for each situation: Waves converging for v < vw, distinct wave fronts for v = vw, and shock waves diverging for v > vw.)

70. What is the Doppler effect?    The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer moving relative to the wave source.

71. If a galaxy was blue shifted, is the galaxy moving toward or away from Earth?    If a galaxy is blue shifted, it is moving toward Earth.

72. Explain how you can hear a sonic boom.    You can hear a sonic boom when a shock wave created by an object traveling faster than sound waves reaches your ears, resulting in a sudden loud noise.

73. List the order of the sections of the electromagnetic spectrum from smallest wavelength to longest wavelength.    The order is: gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves, and radio waves.

THERMAL ENERGY AND HEAT

74. The total energy in a substance is called thermal energy. You can tell if a substance has more thermal energy than another substance by comparing their temperatures and mass; a substance at a higher temperature or larger mass has more thermal energy.

75. True or False. Heat and thermal energy are the same thing. Explain.
    False. Heat refers to the transfer of thermal energy from one substance to another due to a temperature difference, while thermal energy is the total energy of all the particles in a substance.

76. The total energy of all the particles in a substance is called internal energy.

77. Which has more thermal energy, a red hot tack or an iceberg?
    A red hot tack has more thermal energy than an iceberg due to its higher temperature, despite the iceberg having a larger mass.

78. Compare the three temperature scales in terms of water freezing and boiling. Which is mostly widely used throughout the world?
    The Celsius scale has water freezing at 0°C and boiling at 100°C, the Fahrenheit scale has freezing at 32°F and boiling at 212°F, while the Kelvin scale has freezing at 273.15 K and boiling at 373.15 K. The Celsius scale is the most widely used throughout the world.

79. What process is illustrated by the statement, “a thermometer measures its own temperature?” Explain.
    This illustrates thermal equilibrium, where the thermometer reaches the same temperature as the substance it is measuring, allowing it to accurately indicate the substance's temperature.

80. This is also called the absolute temperature scale.
    The Kelvin scale is also called the absolute temperature scale.

81. What temperature is at -273.15 oC? Why is it not possible to reach this temperature?
    -273.15 °C corresponds to absolute zero (0 K). It is not possible to reach this temperature because it represents a state where all particle motion ceases, as defined by the laws of thermodynamics.

82. Explain what is specific heat capacity? What natural substance has a very high specific heat capacity?
    Specific heat capacity is the amount of heat required to raise the temperature of 1 kg of a substance by 1°C. Water has a very high specific heat capacity.

83. If steel has a specific heat capacity more than twice that of aluminum and equal masses of both metals are heated in an open flame, which one will increase in temperature faster?
    Aluminum will increase in temperature faster because it has a lower specific heat capacity compared to steel.

84. Explain why deserts can be very hot in the daytime but very cold when the sun goes down.
    Deserts experience high heat during the day due to low humidity and lack of vegetation, which helps retain heat. At night, the absence of clouds and moisture allows heat to escape quickly, leading to colder temperatures.

85. Distinguish between conduction, convection, and radiation.
    Conduction is the transfer of heat through direct contact between materials, convection is the transfer of heat through the movement of fluids (liquids or gases), and radiation is the transfer of heat through electromagnetic waves without needing a medium.

86. Explain why the east coast and the west coast have such different climates.
    The east coast has a more continental climate influenced by land, while the west coast has a maritime climate influenced by ocean currents, particularly the warmer Pacific Ocean currents affecting temperatures and precipitation patterns.

87. What determines the direction of heat flow?
    The direction of heat flow is determined by temperature differences; heat always flows from hotter objects to colder ones.

88. What happens to a steel ring when it is heated? Explain.
    When a steel ring is heated, it expands. The particles in the steel gain kinetic energy and move farther apart, increasing the overall size of the ring.

89. Explain why it is not a good idea to top off the gas tank in your car in the summertime.
    Topping off the gas tank can lead to overfilling, which may cause gasoline to expand and leak out as it warms up, potentially causing environmental hazards and loss of fuel.

90. How can you use the concepts of thermal expansion to remove a tight metal lid off of a glass jar?
    You can use thermal expansion by running hot water over the metal lid; the lid expands more than the jar due to the heat, making it easier to open.

91. The bottom layer of water on Lake Michigan is what temperature? How do you know this if you’re in MA?
    The bottom layer of water on Lake Michigan is typically colder than the surface water during summer. You can infer its temperature based on seasonal patterns and general knowledge of lake thermodynamics, even if you are in Massachusetts.

PHASE CHANGE AND THERMODYNAMICS

92. How does boiling water in Andover compare to boiling water in the Rocky Mountains?
    Boiling water in Andover (which is at sea level) occurs at 100°C, while in the Rocky Mountains, due to the higher elevation, water boils at a lower temperature because of reduced atmospheric pressure.

93. Describe the differences between a conductor and an insulator.
    Conductors allow the flow of electric current and heat easily due to their free-moving electrons (e.g., metals), whereas insulators resist the flow of heat and electricity (e.g., rubber, glass) due to tightly bound electrons.

94. What makes metals good heat conductors?
    Metals have free electrons that can move easily throughout their structure, allowing them to transfer thermal energy rapidly.

95. Changing phase directly from solid to gas is called what?
    This process is called sublimation.

96. Changing phase from liquid to solid is called? From solid to liquid is called?
    Changing phase from liquid to solid is called freezing, while changing from solid to liquid is called melting.

97. This is the amount of energy needed to transition between solid and liquid.
    This is referred to as the latent heat of fusion.

98. Changing phase from liquid to gas is called? From gas to liquid is called?
    Changing phase from liquid to gas is called vaporization, and from gas to liquid is called condensation.

99. This is the amount of energy needed to transition between liquids and gases.
    This amount of energy is known as the latent heat of vaporization.

100. Explain why water doesn’t get any hotter on a stove once it starts to boil. Where is the heat of the stove going?
     Once water starts boiling, the heat energy is used to convert water from liquid to gas (steam) rather than raising its temperature. The heat from the stove is going into breaking the bonds between water molecules to facilitate this phase change.

101. Explain why boiling is a cooling process.
     Boiling is a cooling process because the molecules with higher energy escape as vapor, leaving behind lower energy molecules in the liquid, thus reducing the average temperature of the remaining liquid.

102. Why do you feel hotter on a warm humid day versus a warm dry day?
     On a humid day, the high moisture content in the air limits the evaporation of sweat from your skin, reducing the cooling effect and making you feel hotter compared to a dry day where sweat evaporates more efficiently.

103. Describe the process of transferring heat in fluids.
     In fluids, heat is transferred primarily through convection; warmer, less dense fluid rises while cooler, denser fluid sinks, creating circulation patterns that distribute heat.

104. State the first law of thermodynamics.
     The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another, and the total energy of an isolated system remains constant.

105. State the second law of thermodynamics.
     The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, and energy systems tend to become more disordered.

106. State the third law of thermodynamics.
     The third law of thermodynamics states that as the temperature of a system approaches absolute zero, the entropy of the system approaches a minimum value.

107. A substance can emit and absorb energy through this process?
     A substance can emit and absorb energy through the process of radiation.

108. What process is used to keep you cool?
     The process used to keep you cool is evaporation, as sweat evaporates from your skin, it removes heat from your body.

109. Compare and contrast the processes of transferring heat in solids and fluids.
     In solids, heat is transferred through conduction by the vibration of particles in direct contact, while in fluids (liquids and gases), heat is transferred through convection due to the movement of fluid particles.

110. In solid substances, these particles are responsible for transferring thermal energy.
     In solid substances, the atomic lattice structure and the vibrating atoms are responsible for transferring thermal energy through conduction.

111. Can any substance prevent the movement of heat? What does this tell us about insulators?
     No substance can completely prevent the movement of heat. This indicates that insulators reduce heat transfer but cannot stop it entirely; they slow down the flow of thermal energy.

112. Can snow be used as an insulator? Explain.
     Yes, snow can be used as an insulator because it contains trapped air pockets, which reduce heat transfer due to low thermal conductivity.

113. Why can you quickly reach into a red hot 450 °C pizza oven to remove the yummy treat without getting severely burned? What happens if, by accident, you touch the sides of the oven?
     You can quickly reach in because of the short duration of contact and air’s low heat capacity; however, touching the sides of the oven, which are solid and have a high thermal conductivity, can transfer heat quickly, causing burns.

114. This process transfers energy without a medium.
     The process that transfers energy without a medium is called radiation.

115. How is temperature related to frequency and wavelength?
     Temperature is directly related to the average kinetic energy of particles, which influences frequency (higher temperature leads to higher frequencies) and inversely related to wavelength (higher frequency leads to shorter wavelengths).

116. What color should you paint your house to keep it cooler in the summer and warmer in the winter? Explain.
     You should paint your house white or light colors to reflect sunlight and heat away in the summer, while in winter, darker colors can absorb more heat from sunlight.

117. Can there be any substances that are perfect reflectors? Explain.
     In theory, no substances can be perfect reflectors due to absorption and scattering; however, some materials come close, such as highly polished metals, which reflect most visible light but still have some absorption.

118. The earth is not a star so therefore it must not emit any radiation. Can you defend this statement? Why or why not?
     This statement is incorrect as the Earth emits radiation in the form of infrared radiation due to its temperature, despite not being a star. All objects above absolute zero emit radiation as a function of their temperature according to Planck's law.

RADIOACTIVITY

119. What particles are found in the nucleus of an atom?

The nucleus of an atom contains protons and neutrons.
   
120. What is the atomic number?

The atomic number is the number of protons in the nucleus of an atom, which defines the element.
   
121. What is an AMU?

AMU stands for atomic mass unit, a unit of mass used to express atomic and molecular weights, where 1 AMU is defined as one twelfth of the mass of a carbon-12 atom.
   
122. Describe the difference between atomic number and atomic mass number.

The atomic number is the number of protons in an atom, while the atomic mass number is the total number of protons and neutrons in the nucleus.
   
123. How do isotopes differ?

Isotopes are variants of the same element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses.
   
124. Distinguish between alpha, beta, and gamma decays of radioactive elements.

Alpha decay involves the emission of an alpha particle (2 protons and 2 neutrons), beta decay involves the transformation of a neutron into a proton with the emission of an electron, and gamma decay involves the emission of gamma rays, which are high-energy electromagnetic waves.
   
125. What is meant by a half-life?

A half-life is the time required for half of the radioactive nuclei in a sample to decay into a different element or isotope.
   
126. Draw a graph showing the rate of decay for a radioactive isotope.

(Drawing Description: Illustrate a graph with time on the x-axis and quantity of the isotope remaining on the y-axis, showing an exponential decay curve.)
   
127. Distinguish between nuclear fission and nuclear fusion.

Nuclear fission is the process of splitting a heavy nucleus into smaller nuclei along with the release of energy, while nuclear fusion is the process of combining light nuclei to form a heavier nucleus, also releasing energy.
   
128. Describe the relationship between critical mass and chain reaction.

Critical mass is the minimum mass of fissile material needed to sustain a nuclear chain reaction; if the mass is below this, the reaction will fizzle out, but if it's above, a sustained chain reaction can occur.
   
129. What element holds its nucleons tighter than any other element?

Iron (Fe) holds its nucleons tighter than any other element due to its binding energy per nucleon.

(Drawing Description: Illustrate a graph showing binding energy per nucleon versus mass number, highlighting iron as having the peak binding energy.)