Download 101 Facts you NEED to know - Sewanhaka Central High School

101 Facts you NEED to know
Mechanics
1. Weight (force of gravity) decreases as you move away from the earth by distance
squared.
2. Mass and inertia are the same thing.
3. Constant velocity and zero velocity means the net force is zero and acceleration is
zero.
4. Weight (in newtons) is mass x acceleration (w = mg). Mass is not weight!
5. Velocity, displacement [s], momentum, force and acceleration are vectors.
6. Speed, distance [d], time, and energy (joules) are scalar quantities.
7. The slope of the velocity-time graph is acceleration.
8. At zero (0) degrees two vectors have a resultant equal to their sum. At 180
degrees two vectors have a resultant equal to their difference. From the difference
to the sum is the total range of possible resultants.
9. Centripetal force and centripetal acceleration vectors are toward the center of the
circle- while the velocity vector is tangent to the circle.
10. An unbalanced force (object not in equilibrium) must produce acceleration.
11. The slope of the distance-tine graph is velocity.
12. The equilibrant force is equal in magnitude but opposite in direction to the
resultant vector.
13. Momentum is conserved in all collision systems.
14. Magnitude is a term use to state how large a vector quantity is.
Energy
15. Mechanical energy is the sum of the potential and kinetic energy.
16. Units: a = [m/sec2], F = [kg•m/sec2] (newton), work = pe= ke = [kg•m2/sec2]
(joule)
17. An ev is an energy unit equal to 1.6 x 10-19 joules
18. Gravitational potential energy increases as height increases.
19. Kinetic energy changes only if velocity changes.
20. Mechanical energy (pe + ke) does not change for a free falling mass or a swinging
pendulum. (when ignoring air friction)
21. The units for power are [joules/sec] or the rate of change of energy.
Electricity
22. A coulomb is charge, an amp is current [coulomb/sec] and a volt is potential
difference [joule/coulomb].
23. Short fat cold wires make the best conductors.
24. Electrons and protons have equal amounts of charge (1.6 x 10-19 coulombs each).
25. Adding a resistor in parallel decreases the total resistance of a circuit.
26. Adding a resistor in series increases the total resistance of a circuit.
27. All resistors in series have equal current (I).
28. All resistors in parallel have equal voltage (V).
29. If two charged spheres touch each other add the charges and divide by two to find
the final charge on each sphere.
30. Insulators contain no free electrons.
31. Ionized gases conduct electric current using positive ions, negative ions and
electrons.
32. Electric fields all point in the direction of the force on a positive test charge.
33. Electric fields between two parallel plates are uniform in strength except at the
edges.
34. Millikan determined the charge on a single electron using his famous oil-drop
experiment.
35. All charge changes result from the movement of electrons not protons (an object
becomes positive by losing electrons)
36. Charging by conduction means contact and the electroscope acquires the same
charge as the charged rod
37. Charging by induction means there is no contact and the electroscope acquires a
charge opposite that of the charged rod
38. Neutral objects attract to both positive and negative objects.
39. Ammeters have low resistance and are wired in series. Voltmeters have high
resistance and are wired in parallel
Magnetism
40. The direction of a magnetic field is defined by the direction a compass needle
points.
41. Magnetic fields point from the north to the south pole
Wave Phenomena
42. Sound waves are longitudinal and mechanical.
43. Light slows down, bends toward the normal and has a shorter wavelength when it
enters a higher (n) value medium.
44. All angles in wave theory problems are measured to the normal.
45. Blue light has more energy. A shorter wavelength and a higher frequency than red
light (remember- ROYGBIV).
46. The electromagnetic spectrum (radio, infrared, visible. Ultraviolet x-ray and
gamma) are listed lowest energy to highest.
47. A prism produces a rainbow from white light by dispersion (red bends the least
because it slows the least).
48. Light wave are transverse (they can be polarized).
49. The speed of all types of electromagnetic waves is 3.0 x 108 m/sec in a vacuum.
50. The amplitude of a sound wave determines its energy.
51. Constructive interference occurs when two waves are zero (0) degrees out of
phase or a whole number of wavelengths (360 degrees.) out of phase.
52. At the critical angle a wave will be refracted to 90 degrees.
53. According to the Doppler effect a wave source moving toward you will generate
waves with a shorter wavelength and higher frequency.
54. Double slit diffraction works because of diffraction and interference.
55. Single slit diffraction produces a much wider central maximum than double slit.
56. Diffuse reflection occurs from dull surfaces while regular reflection occurs from
mirror type surfaces.
57. As the frequency of a wave increases its energy increases and its wavelength
decreases.
58. Transverse wave particles vibrate back and forth perpendicular to the wave
direction.
59. Wave behavior is proven by diffraction, interference and the polarization of light.
60. Shorter waves with higher frequencies have shorter periods.
61. Radiowaves are electromagnetic and travel at the speed of light (c).
62. Monochromatic light has one frequency.
63. Coherent light waves are all in phase.
Geometric Optics
64. Real images are always inverted.
65. Virtual images are always upright.
66. The normal line is always 90o to the mirror/lenses
67. ALL rays obey the law of reflection
68. In a plane mirror, the images is the same size as the object.
Modern Physics
69. The particle behavior of light is proven by the photoelectric effect.
70. A photon is a particle of light {wave packet}.
71. Large objects have very short wavelengths when moving and thus can not be
observed behaving as a wave. (DeBroglie Waves)
72. All electromagnetic waves originate from accelerating charged particles.
73. The frequency of a light wave determines its energy (E = hf).
74. The lowest energy state of a atom is called the ground state.
75. Increasing light frequency increases the kinetic energy of the emitted photoelectrons.
76. As the threshold frequency increase for a photo-cell (photo emissive material) the
work function also increases.
77. Increasing light intensity increases the number of emitted photo-electrons but not
their KE.
Internal Energy
78. Internal energy is the sum of temperature (ke) and phase (pe) conditions.
79. Steam and liquid water molecules at 100 degrees have equal kinetic energies.
80. Degrees Kelvin (absolute temp.) Is equal to zero (0) degrees Celsius.
81. Temperature measures the average kinetic energy of the molecules.
82. Phase changes are due to potential energy changes.
83. Internal energy always flows from an object at higher temperature to one of lower
temperature.
Nuclear Physics
84. Alpha particles are the same as helium nuclei and have the symbol
85. The atomic number is equal to the number of protons (2 for alpha)
.
86. Deuterium ( ) is an isotope of hydrogen ( )
87. The number of nucleons is equal to protons + neutrons (4 for alpha)
88. Only charged particles can be accelerated in a particle accelerator such as a
cyclotron or Van Der Graaf generator.
89. Natural radiation is alpha (
), beta ( ) and gamma (high energy x-rays)
90. A loss of a beta particle results in an increase in atomic number.
91. All nuclei weigh less than their parts. This mass defect is converted into binding
energy. (E=mc2 from Kg to J) (1u=931MeV for small amounts)
92. Isotopes have different neutron numbers and atomic masses but the same number
of protons (atomic numbers).
93. Geiger counters, photographic plates, cloud and bubble chambers are all used to
detect or observe radiation.
94. Rutherford discovered the positive nucleus using his famous gold-foil experiment.
95. Fusion requires that hydrogen be combined to make helium.
96. Fission requires that a neutron causes uranium to be split into middle size atoms
and produce extra neutrons.
97. Radioactive half-lives can not be changed by heat or pressure.
98. One AMU of mass is equal to 931 meV of energy (E = mc2).
99. Nuclear forces (weak and strong) are strong and short ranged.
100.
An anti particle has the same mass but the opposite charge of its real
particle.
General
101.
The most important formulas in the physics regents are:
Name _____________________________________
Quiz on Facts #1- Mechanics
1. Sketch the relationship between the force of gravity between the moon and a
planet as a function of distance between the moon and the center of the planet.
Fg
r
2. Inertia depends on mass and velocity
TRUE
or
FALSE (circle one)
3. If an object has a net force of zero
a. Its velocity is zero
b. Its velocity is constant
c. Its acceleration is zero
d. All of the above
4. When standing on Earth, which has a larger magnitude, my mass in Kg or my
weight in Newtons? __________________________
5. What do the terms velocity, displacement, force, and acceleration all have in
common? __________________________________________________.
6. If I find the slope of a velocity vs. time graph to be 10, the units of this number
should be __________________________ which means it tells me about the
_________________________ of the object.
7. The area under a velocity vs. time graph tells me the object’s
_________________________.[
8. The maximum net force is produced when two forces point
_________________________________ which is a _______ degree angle. To
find this resultant you must _______________ the magnitudes of the forces.
9. When moving in a circle, the force acting on the object points
_______________________, the acceleration of the object points
______________________, and the velocity of the object points
____________________________________.
10. Any unbalanced (net force) causes an object to __________________________
in a direction that is _________________________ as the unbalanced force.
11. The minimum net force is produced when two forces point
_________________________________ which is a _______ degree angle. To
find this resultant you must _______________ the magnitudes of the forces
12. What do the terms distance, speed, time, mass, and energy all have in common?
_________________________________________________________
13. The slope of a displacement vs. time graph is found to be 5. The units of this
number are ______________________ which means it tells me about the object’s
_________________________.
14. What is the name of the force that will produce a net force of zero?
_________________________________.
15. What is the name of the force that is defined as the sum of all forces acting on an
object? ___________________________________________________
16. Momentum is calculated by the formula _____________________________.
17. Momentum is always conserved in any collision TRUE
18. Energy is always conserved in any collision TRUE
19. The equilibrant force has the SAME / OPPOSITE
but the SAME / OPPOSITE direction.
or
or FALSE (circle one)
FALSE (circle one)
magnitude as the resultant
20. As you move away from the Earth’s surface, you mass
__________________________ and your weight _________________________.
Name _____________________________________
Quiz on Facts #2- Energy and Internal Energy
1. The unit of energy is ______________________ which has the base units of
__________________________.
2. The unit of work is ________________________ which is THE SAME AS /
DIFFERENT FROM (circle one) the units of energy.
3. To calculate mechanical energy you __________________________________
______________________________________________________________
4. What is the unit used to measure very small amounts of energy ______________
5. What type of energy do you have when you are above the ground? ____________
6. What type of energy do you have when you are moving? __________________
7. What type of energy do you have when you are attached to a stretched spring?
____________________________
8. Give an example of when you can set your gravitational potential energy equal to
your kinetic energy.
___________________________________________________________
9. What is the rate at which you use energy? ________________________ which
has the units of _______________________________.
10. Internal energy is related to the _____________________ of an object
11. internal energy flows from ___________________ objects to
___________________ objects.
Name _____________________________________
Quiz on Facts #3- Waves /Optics
1. Sound waves are mechanical / electromagnetic (circle one) which
means___________________________________________________ and they
are longitudinal / transverse (circle one) which means ______________________
______________________________________________________________
2.
Light waves are mechanical / electromagnetic (circle one) which
means___________________________________________________ and they
are longitudinal / transverse (circle one) which means _____________________
_________________________________________________________________.
3. When light enters a medium of a higher index of refraction its speed
____________________, its wavelength ________________________, its
frequency ___________________________, and it bends
____________________ the normal.
4. When light enters a medium of a lower index of refraction its speed
____________________, its wavelength ________________________, its
frequency ___________________________, and it bends
____________________ the normal.
5. Critical angle occurs when light passes from HIGH TO LOW INDEX
/
LOW TO HIGH INDEX (circle one) and the angle of refraction is __________
degrees.
6. All angles in diagrams are measured relative to _______________________
7. Compared to RED light, Blue light has ________________ frequency,
_____________________ energy, _____________________ wavelength,
__________________________ speed in a vacuum.
8. All waves in the electromagnetic spectrum have the same _________________.
9. Dispersion causes ________________________________________________.
10. ____________________ waves can be polarized.
11. A sound wave’s energy (volume) is determined by its ____________________.
12. Constructive interference occurs when the phase difference between two waves is
____________________ decrees. Which means they are ____ ____________.
The path length difference is _________________ a wavelength.
13. When a wave source is moving towards you, you will observe a
________________ frequency, and _____________________ wavelength which
means a _________________ pitch and a ____________ shift in color. The name
of this phenomena is the __________ ______________.
14. What two wave phenomena are illustrated in the double slit experiment?
__________________ and _____________________.
15. ________________ reflection occurs off a smooth surface and
___________________ reflection occurs off of a rough surface.
16. As the energy of light increases, the frequency _______________________ and
the wavelength _________________________.
17. Wave behavior is proven by _______________________ ,
____________________ and ____________________________.
18. Waves with short periods have __________________ frequencies and
__________________ wavelengths.
19. Radio waves travel at ______________________.
20. Monochromatic light means __________________________.
21. LASERS produce ______________________ light which means it is all in phase.
22. Real images are always ____________________________
23. Virtual images are always ___________________________
24. The normal line is always _________________ degrees to the mirror/lens
25. The image is _________________ in size compared to the object in a plane
mirror
Name _____________________________________
Quiz on Facts #4- Modern /Nuclear
1. ____________________________ experiment shows light behaves like a wave.
2. _____________________________ experiment shows light behaves like a
particle.
3. A packet of light is called a _________________ which contains a
__________________ amount of energy
4. You created electromagnetic waves by _____________________ charged
particles
5. The _____________________ of light determines its energy.
6. The lowest energy of an atom is called the ______________________________.
7. During the photoelectric effect, increasing the frequency of the light changes the
_______________________ of the emitted electrons. Increasing the brightness of
the light changes the _________________________ of the emitted electrons.
8. The work function describes how _____________________________________.
As the work function increases, the threshold frequency ___________________.
9. An alpha particle has ________ protons and ________ neutrons.
10. The atomic number is equal to the number of _____________ an atom has
11. Nucleons are ______________________ and _____________________.
12. In order to be accelerated in a machine, a particle must have
__________________.
13. The total mass of all the parts of an element is __________________ than the
mass of the actual element. This is known as ____________________________.
14. To convert from mass defect to binding energy use the conversion
___________________________________________.
15. To change from Kilograms of mass to Joules of energy use _________________.
16. Two main observations made in Rutherford’s gold foil experiment were that
_____________________________ and __________________________.
17. Fusion occurs when __________________________________________ and
_______________ energy. Fusion occurs in ___________________________.
18. Fission occurs when ________________________________ and
________________ energy. Fission occurs in _______________________.
19. The two short range fundamental forces are _______________________ and
_____________________________.
20. An anti particle has the _______________ mass and the __________________
charge of its sister particle.
Name _____________________________________
Quiz on Facts #5- Electricity /Magnetism
1. A coulomb is a unit of _________________, an Amp (=
/
) is a unit of
_________________, and a volt (= /
) is a unit of ___________________.
2. Wires that are ______________, ________________, and _______________
make the best conductors.
3. Electrons and protons have the ___________________ amount of charge.
4. If a resistor is added in series the total resistance of the circuit _______________.
5. If a resistor is added in parallel the total resistance of the circuit ______________.
6. In series the __________________ of each resistor is the same.
7. In parallel the ______________________ of each resistor is the same
8. If two charged conducting spheres are touched together, to find the resulting
charge on each, you should ___________________________________________
9. Insulators contain ___________________ electrons while conductors contain
_____________________ electrons.
10. You can conduct current by using _____________________ and
______________________.
11. Electric fields point the way a _____________________ charge would move.
12. The Electric field between parallel plates is ___________________ which means
charges placed in between the plates feel ______________________ forces.
13. Millikan used his oil drop experiment to determine the
_________________________ of an electron.
14. Charging by conduction means you CAN / CAN NOT (circle one) touch the
electroscope with the charged rod, and the electroscope will end up with the
SAME / OPPOSITE (circle one) charge as the rod used.
15. Charging by induction means you CAN / CAN NOT (circle one) touch the
electroscope with the charged rod, and the electroscope will end up with the
SAME / OPPOSITE (circle one) charge as the rod used.
16. If a negatively charged object attracts an unknown object, we know that unknown
object ____________________________________________.
17. When charging objects, the ________________ are gained or lost, which means
objects become negative by ___________________________________ and
objects become positive by _________________________________________.
18. Magnetic field lines point from _________________ to __________________.
19. Ammeters have ______________ resistance and are wired in _____________.
Voltmeters have ________________ resistance and are wired in _____________.