Physics Flashcards
(121 cards)
1
Q
fundamental units
A
seven basic units of the SI measurement system: kilogram, second, mole, meter, ampere, Kelvin, candela
2
Q
derived unis
A
units that are combinations of fundamental units
3
Q
accuracy
A
indication of how close a measurement is to the accepted value
4
Q
precision
A
indication of agreement among a number of measurements made in the same way
5
Q
random uncertainty
A
uncertainty produced by unknown and unpredictable variables in the experimental situation (can be reduced by repeated trials)
6
Q
systematic error
A
error associated with a particular instrument that causes the measured value to be off by the same amount each time (can be eliminated by fixing sources of error - results in non-zero y-intercept)
7
Q
absolute uncertainty
A
uncertainty expressed as an exact quantity
8
Q
fractional uncertainty
A
uncertainty expressed as a ratio
9
Q
percentage uncertainty
A
uncertainty expressed as a percentage
10
Q
vector
A
quantity with magnitude and direction
11
Q
scalar
A
quantity with magnitude only
12
Q
distance
A
total movement along a path
13
Q
displacement
A
distance traveled from a fixed point in a particular direction
14
Q
velocity
A
rate of change of displacement
15
Q
speed
A
rate of change of distance
16
Q
average velocity
A
total displacement divided by total time
17
Q
instantaneous velocity
A
velocity at a specific moment
18
Q
acceleration
A
rate of change of velocity
19
Q
Newton’s first law of motion
A
object at rest remains at rest and an object in motion remains in motion at a constant speed in a straight line unless acted on by an unbalanced force
20
Q
Newton’s second law of motion
A
unbalanced force will cause an object to accelerate in the direction of the net force
21
Q
Newton’s third law of motion
A
when two bodies A and B interact, the force that A exerts on B is equal and opposite to the force that B exerts on A
22
Q
translational equilibrium
A
net force acting on a body is zero
23
Q
linear momentum
A
product of mass and velocity
24
Q
impulse
A
change in momentum
25
law of conversation of linear momentum
total momentum of an isolated system remains constant
26
work
product of a force on an object and the displacement of the object in the direction of the force
27
kinetic energy
product of 1/2 times the mass of an object times the square of an object's speed
28
change in gravitational potential
product of an object's mass times the gravitational field strength times the change in height
29
elastic potential energy
energy stored as a result of deforming an elastic material such as a spring
30
principle of conservation of energy
total energy of an isolated system remains constant
31
elastic collision
collision in which kinetic energy is conserved
32
inelastic collision
collision in which kinetic energy is not conserved
33
power
rate at which work is done
34
efficiency
ratio of useful energy output to total energy input
35
Temperature
measure of the average random kinetic energy of all the particles of a substance
36
Thermal Equilibrium
two objects are in thermal equilibrium when they are at the same temperature so that there is no transfer of thermal energy between them
37
Internal Energy of a substance
The total potential energy and random kinetic energy of the molecules of the substance.
38
Thermal Energy
energy transferred between two substances by nonmechanical means
39
Specific Heat Capacity
amount of energy per unit mass required to raise the temperature of a substance by 1K
40
Thermal Capacity
amount of energy required to raise the temperature of a substance by 1K
41
Boiling
phase change of a liquid into a gas that occurs at a fixed temperature
42
Evaporation
when faster moving molecules have enough energy to escape from the surface of a liquid that is at a temperature less than its boiling point, leaving slower moving molecules behind which results in a cooling of the liquid
43
Specific Latent Heat
amount of energy per unit mass required to change phase of a substance at constant temperature and pressure
44
Pressure
force per unit area acting on a surface
45
Ideal Gas
gas that follows the ideal gas equation of state (PV = nRT) for all values of P, V, and T
46
Real Gas
gas that does not follow the ideal gas equation of state for all values of P, V, and T
47
Absolute Zero of Temperature
temperature at which a gas would exert no pressure
48
Kelvin scale of Temperature
absolute scale of temperature in which 0 K is the absolute zero of temperature
49
Displacement (for waves)
distance in a particular direction of a particle from its mean position
50
Amplitude
maximum displacement from the mean position
51
Frequency
number of oscillations per unit time
52
Period
time taken for one complete oscillation
53
Phase Difference
difference in phase between the particles of two oscillating systems
54
Simple Harmonic Motion
motion that takes place when the acceleration of an object is proportional to its displacement from its equilibrium position and is always directed toward its equilibrium position
55
Damping
the result of a force that acts on a system in the opposite direction to the direction of motion of the oscillating particle
56
Critical Damping
when a resistive force is applied to an oscillating system that causes the particle to return to zero displacement in a minimum amount of time
57
Resonance
transfer of energy in which a system is subject to an oscillating force that matches the natural frequency of the system resulting in a large amplitude of vibration
58
Wave Pulse
single oscillation or disturbance in a medium
59
Traveling Wave
series of periodic pulses that involves a transfer of energy although there is no net motion of the medium through which the wave travels
60
Transverse Wave
wave in which the direction of motion of the energy transfer (the wave) is perpendicular to the direction of motion of the particles of the medium
61
Longitudinal Wave
wave in which the direction of motion of the energy transfer (the wave) is parallel to the direction of motion of the particles of the medium
62
Wavefront
collection of neighboring points on a wave that are in phase
63
Ray
line drawn perpendicular to a wavefront indicating the direction of motion of the energy transfer
64
Crest
top of a transverse wave
65
Trough
bottom of a transverse wave
66
Compression
area of high pressure in a longitudinal wave
67
Rarefaction
area of low pressure (expansion) in a longitudinal wave
68
Wavelength
shortest distance along the wave between two points in phase with one another
69
Wave Speed
speed of transfer of the energy of the wave
70
Intensity
power per unit area
71
Law of Reflection
The angle of incidence is equal to the angle of reflection when both angles are measured with respect to the normal line
72
Refractive Index
the ratio of the speed of the wave in the refracted medium to the speed of the wave in the incident medium
73
Snell’s Law
ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for a given frequency.
74
Principle of Superposition
When two or more waves meet, the displacement of the resultant wave is the vector sum of the displacements of the component waves.
75
Constructive Interference
superposition of two or more pulses or waves in phase
76
Destructive Interference
superposition of two or more pulses or waves out of phase
77
Standing (stationary) wave
resultant wave formed when two waves of equal amplitude and frequency traveling in opposite directions in the same medium interfere
78
Node
locations of constant complete destructive interference on a standing wave
79
Antinode
locations of maximum constructive interference on a standing wave
80
Fundamental (First Harmonic)
lowest frequency mode of vibration of a standing wave
81
Polarized Light
light in which the electric field vector vibrates in one plane only
82
Polarizer
device that produces plane polarized light from an unpolarized beam
83
Diffraction
the bending or spreading of a wave when it passes through a small opening (aperture) or around a barrier
84
Electric Field
a region of space where a small test charge experiences a force due to its charge
85
Law of Conservation of Electric Charge
total electric charge of an isolated system remains constant
86
Conductor
material through with electric charge flows freely
87
Insulator
material through which electric charge does not flow freely
88
Coulomb’s Law
The electric force between two point charges is directly proportional to the product of the two charges and inversely proportional to square of the distance between them, and directed along the line joining the two charges.
89
Electric Field Strength
Electric force per positive unit test charge
90
Electric Potential Difference
The amount of work done per unit charge in taking a small positive test charge from one point to another
91
Electric Potential Energy
energy that a charge has due to its position in an electric field
92
Electronvolt
energy gained by an electron moving through an electric potential difference of one volt
93
Electric Current
current is defined in terms of the force per unit length between parallel current-carrying conductors, but it is equivalent to charge per unit time
94
Electron Drift Speed
average speed of electrons through a conductor due to an electric field
95
Direct Current
current in which electrons flow in the same direction with the same drift speed
96
Resistance
ratio of potential difference applied across a piece of material to the current through the material
97
Resistivity
resistance times length per unit of cross sectional area
98
Resistor
device with a constant resistance (Ohmic device) over a wide range of potential differences
99
Ohm’s Law
For a conductor at constant temperature, the current flowing through it is proportional to the potential difference across it
100
Ohmic Device
A device that obeys Ohm’s law for a wide range of potential differences
101
Non-Ohmic Device
A device that does not obey Ohm’s law
102
Cell
a single unit converting chemical energy to electrical through electrolysis – a battery is technically two or more cells
103
Primary cell
Single use cell (non-rechargeable)
104
Secondary cell
Cell in which the chemical process is reversible (rechargeable)
105
Electromotive Force
total energy per unit charge supplied by the battery around a circuit
106
Internal Resistance
resistance supplied by the materials within the device
107
Ideal Ammeter
one with zero internal resistance – must be placed in series
108
Ideal Voltmeter
one with infinite internal resistance – must be placed in parallel
109
Series
Two components are connected in series if they are on a single path – current through each component is the same
110
Parallel
Two components are connected in parallel if the current splits immediately before the components and rejoins immediately after
111
Kirchhoff’s Current Law
The sum of the individual currents into a junction is zero – total current in equals total current out
112
Kirchhoff’s Voltage Law
The sum of the voltages around any closed loop is zero – total potential supplied (raised) equals total potential used (lowered)
113
Potential Divider
two resistors placed in series that divide up the battery’s potential difference
114
Direction of a Magnetic Field
direction that the North pole of a small test compass would point if placed in the field (N to S)
115
Field
region of space where a mass or charge experiences a force
116
Newton’s Universal Law of Gravitation
force of gravity between two objects is directly proportional to the product of the two masses and inversely proportional to the square of the distance between them and acts along a line joining their centers
117
Gravitational Field Strength
gravitational force per unit mass exerted on a small or point mass
118
Nuclide
particular type of nucleus with a certain number of protons and neutrons
119
Isotope
nuclei with the same number of protons (Z) but different number of neutrons (N)
120
Nucleon
a proton or neutron
121
Mass Number
number of nucleons (protons + neutrons) in nucleus
