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Physics Flashcards

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1
Q

Centrifugal Force (direction)

A

Antiparallel to centripetal force vector. Points away from center of circle in uniform circular motion.

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2
Q

One dimensional motion equations

A 
v_f = v_o + at
x = v_o*t + .5*at
v_f^2 = v_o^2 + 2ax
x = v_avg * t
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3
Q

Gravitational Force Equation

A 
F_g = G*m_1*m_2 / r^2
(G = 6.67*10^-11 Nm^2/kg^2)
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4
Q

Forces of gravity along inclined plane

A 
F_g,parallel = mgsin(theta)
F_g,perp = mgcos(theta)
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5
Q

Centripetal force equation

A

F_c = mv^2 / r

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6
Q

Torque equation

A

t = r X F (cross product), or t = rFsin(theta)

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7
Q

Unit of Illuminous Intensity

A

Candela (cd)

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8
Q

Work equations

A 
W = F (dot) d = Fdcos(theta)
W = delta KE = 0.5*m(v_f^2 - v_i^2)
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9
Q

Isochoric Process

A

AKA isovolumetric. Pressure of a gas is changed, but there is no change in volume. No work is done.

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10
Q

Area under P-V curve

A

Equal to work done in a thermodynamic system

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11
Q

Conservative forces (def and ex)

A

Def: path-independent forces that do not dissipate). Ex: gravity, electrostatic forces

Also, friction is NOT a conservative force because the amount of work done by this force depends on the specified path

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12
Q

Work during uniform circuar motion

A

No work is done because the displacement vector and force vector are always perpendicular

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13
Q

Isobaric Process

A

Pressure remains constant. W = P * deltaV

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14
Q

Positive Work

A

The directions of the exerted force and the displacement are in the same direction

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15
Q

When is work negative?

A

When the signs of the force and displacement are opposite

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16
Q

Power

A

The rate at which energy is transferred from one system to another. P = W / t = deltaE / t

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17
Q

Mechanical Advantage

A

Ratio of the magnitudes of the force exerted on an object by a simple machine (F_out) to the force actually applied on the simple machine (F_in). M.A. = F_out/F_in

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18
Q

Efficiency

A

Ratio of work put into a system to work put out by a system

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19
Q

The six simple machines

A

Inclined plane, wedge, pulley, wheel and axle, lever, screw

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20
Q

Higher Horsepower Cars

A

This only means that the car will reach any given velocity faster than cars with lower horsepowers.

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21
Q

First Law of Thermodynamics

A

delta U = Q - W. Total change in internal energy of a system is equal to the amount of energy transferred into the system by as heat minus the amount of energy that leaves the system as work.

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22
Q

Entropy of an isolated system

A

Increases for all real (irreversible) processes

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23
Q

Second Law of Thermodyamics

A

Objects in thermal contact and not in thermal equilibrium will exchange heat energy such that the objects with the higher temperature will give off heat energy to the object with lower temp. until they are at thermal equilibrium.

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24
Q

Conduction

A

Direct transfer of energy from molecule to molecule through collisions. Best conductor = metal. Worst conductor = gases.

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25
Q

Convection

A

Transfer of heat by physical motion of fluid over a material. Only achievable by liquids and gases.

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26
Q

Radiation

A

Transfer of energy by electromagnetic waves. Unique because it can occur through a vacuum (unlike conduction and convection)

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27
Q

Latent heat

A

AKA Heat of transformation (heat per kg required to change phase).

Latent heat = heat transfer / mass –> (L = q/m, q=mL)

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28
Q

Solid to gas

A

Sublimation

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29
Q

Gas to solid

A

Deposition

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30
Q

Liquid to solid

A

Fusion or solidification

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31
Q

Adiabatic

A

No heat exchange. Q = 0, so delta U = -W

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32
Q

Isothermal

A

Constant temperature, so deltaU = 0, Q = W

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33
Q

Isovolumetric

A

No change in volume, so W = 0 and deltaU = Q

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34
Q

Zeroth Law of Thermodynamics

A

When one object is in thermal equilibrium with another, there will be no heat flow between the two

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35
Q

Absolute 0

A

-460 F, -273C, 0 K

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36
Q

Third Law of Thermodynamics

A

The entropy of a perfectly organized crystal at absolute zero is zero

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37
Q

Converting C to F

A

F = 9/5 (C) + 32

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38
Q

Thermal expansion

A

delta L = alpha * L * deltaT, where alpha is the coefficient of linear expansion

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39
Q

Volumetric expansion

A

delta V = beta * V * delta T, where V is the coefficient of volumetric expansion

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40
Q

Coefficient of volumetric expansion

A

beta = 3*alpha,

where alpha is the coefficient of linear expansion

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41
Q

State functions

A

Thermodynamic properties that are a function of only the current equilibrium state of a system. The include: pressure, density, temp, volume, enthalpy, internal energy, Gibbs free energy, and entropy.

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42
Q

Process Function

A

Describe the path taken to get from one state to another (work and heat)

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43
Q

Entropy and the Second Law of Thermodynamics

A

Energy spontaneously disperses from being localized to becoming spread out, if it is not hindered from doing so

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44
Q

Entropy

A

Measure fo the spontaneous dispersal of energy at the specific temperature: how much energy is spread out or how widely spread out energy becomes in a process.

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45
Q

Natural process (heat exchange)

A

Irreversible. Heat transferring from a hot object to a cooler object when the two are in contact. Would be considered unnatural if heat transferred from cooler to hot.

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46
Q

Isolated vs Closed Systems

A

Isolated systems cannot exchange energy or matter with their surroundings. Closed systems can exchange energy, but not matter.

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47
Q

Absolute pressure

A

The sum of all pressures at a certain point within a fluid; Equal to the pressure at the surface of the fluid + the pressure due to the fluid itself.

abs. P = P_surface + P_fluid

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48
Q

Gauge pressure

A

Difference between the absolute pressure and atmospheric pressure. In liquids, gauage pressure is caused by the weight of the liquid above the point of measurement

P_gauge = P_abs - P_atm

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49
Q

Pascal’s Principle

A

The pressure applied to an incompressible fluid will be distributed undiminished throughout the entire volume of the fluid

P = F/A = F_1 / A_1

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50
Q

Hydraulic Machines

A

Operate on the application of Pascal’s principle to generate mechanical advantage

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51
Q

Archimedes’ Principle

A

Governs buyant force. When an object is placed in a fluid, the fluid generates buoyant force against the object that is equal to the wieght of the fluid displaced by the object. Buoyant force point opposite to gravity. Maximum buoyant force is larger than the force of gravity when the object is floating

F_buoy = p_fluid * V_fluid-displaced * g

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52
Q

Cohesive forces

A

Between molecules of the same fluid. Gives rise to surface tension

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53
Q

Adhesive forces

A

Between molecules of different materials

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54
Q

Viscosity

A

Measurement of a fluid’s internal friction. Generates a nonconservative force: viscous drag

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55
Q

Laminar flow

A

Rate is determined by Poiseuille’s Law. Assumes conservation of energy

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56
Q

Continuity equation

A

Q = v_1 * A_1 = v_2 * A_2

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57
Q

Bernouilli’s Eq

A

P_1 + 0.5p(v_1)^2 + pgh = P_2 + 0.5p(v_2)^2 + pgh

Conservation of total mechanical energy

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58
Q

Poiseuille’s Law

A

Allows calculation of flow rate when there is laminar flow through a pipe:

Q = pir^4deltaP / (8viscositylength)

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59
Q

The circulatory system is a ____ loop with a ______ flow rate

A

closed; nonconstant

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60
Q

Why is fluid “lost” from the circulatory system

A

Due to the pressure difference between osmotic and hydrostatic pressure in the blood vessels

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61
Q

T/F: volume of blood entering the heart is greater than the volume of blood exiting the heart with each cycle

A

False - the volumes entering and exiting are equal

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62
Q

Blood vessels with highest resistance

A

Capillaries

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63
Q

How is blood moved back to the heart?

A

Through veins. Motivated by mechanical squeezing of the vessels by skeletal muscles, lower pressure in the heart achieved after systole, and pressure gradient in the thorax created by inhalation and exhalation.

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64
Q

Venturi effect

A

Hydrostatic pressure exerted on the inside of a pipe will be the lowest at the point where the fluid is flowing the fastest

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65
Q

Fundamental Unit of Charge

A

e = 1.6*10^-19 C

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66
Q

Electric Field, Equation, and Direction of E-field lines

A

Def: the ratio of the force that is exerted on a test charge to the magnitude of that charge.

E = kq / r^2

Field lines point away from positive charges and toward negative charges

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67
Q

Electric potential energy

A

U = kQq / r

Increases if opposite charges move apart or same charges move closer. Decreases as opposite charges move closer or same charges move apart.

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68
Q

Electric potential

A

Electric potential energy per unit charge: V = U_e / q

or V = kQ/r (from source charge)

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69
Q

Potential difference

A

Change in potential energy that accomplishes the movement of a test charge from one position to another. Path-independent.

Delta V = V_b - V_a = W_ab / q

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70
Q

Directions of spontaneous movement of positive and negative charges

A

+: move from high PE to low PE

-: move from low PE to high PE

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71
Q

Electric potential due to dipole

A

V = kqd / r^2 * cos(theta)

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72
Q

Dipole moment

A

p = q*d

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73
Q

Electric field on perpendicular bisector of a dipole

A

E = k * p/r^3

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74
Q

Torque on a dipole in an E-field

A

T = pEsin(theta)

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75
Q

1 Tesla =

A

1 Ns / (mC)

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76
Q

Magnetic field due to straight wire

A

B = mu_0 * I / (2pi*r)

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77
Q

Magnetic field due to looped wire

A

B = mu_0 * I / (2r)

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78
Q

Diamagnetic materials

A

No unpaired electrons, slightly repelled by a magnetic field

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79
Q

Paramagnetic materials

A

Some unpaired electrons. Become weakly magnetic in an external field

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80
Q

Ferromagnetic materials

A

Some unpaired electrons. Become strongly magnetic in an external field

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81
Q

Magnetic force due to moving particle

A

F_b = qvB*sin(theta)

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82
Q

Magnetic force due to wire

A

F_b = ILB*sin(theta)

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83
Q

When do electrons in circuits have the highest electric potential energy in a circuit?

A

Just after exiting the battery because none of its potential energy has been converted to kinetic or lost as heat yet.

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84
Q

Ohm’s Law

A

V = I*R

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85
Q

Power in a circuit

A

P = W/t = delta E / t = IV = I^2 * R = V^2/R

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86
Q

Capacitance

A

Def: The ratio of the magnitude of the charge stored on a plate to the potential difference across the capacitor. Defined by area and distance between the plates

C = Q/V = epsilon_0 * A/d

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87
Q

Potential energy stored in a capacitor

A

U = 1/2 * C *V^2

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88
Q

Transformers in circuits (energy)

A

Energy must be conserved, so P_in = P_out

Can be written as I_outV_out = I_inV_in

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89
Q

Superior olive

A

A collection of brainstem nuclei that helps localize sound

90
Q

Transverse waves

A

Those that move perpendicular the oscillation of the wave, which is in the direction of particle oscillation. Ex: visible light microwaves, and Xrays

91
Q

Longitudinal waves

A

Oscillate parallel to the direction of propagation (parallel to the direction of energy transfer). Picture a piston in that these waves involve cycles of compression and decompression along the direction of the wave. Major ex: SOUND

92
Q

Propagation speed of a wave

A

v = freq* wavelength

93
Q

angular frequency

A

*considered in simple harmonic motion in springs and pendula

row = 2pi*freq = 2pi/T

94
Q

Phase difference

What is indicated by a phase difference of 180 degrees?

A

Calculation that shows how in-step or out-pf-step two waves in the same space are.

A phase difference of 180 degrees (half a cycle) means that the max of one wave is the min of the other, so there is destructive interference

95
Q

Standing waves

A

Form when waves of the same frequency are travelling in opposite directions through the same medium. Occur when both ends of the wave are fixed and the only apparent displacement in the amplitudes between the nodes

96
Q

Timbre

A

Quality of sound, determined by natural (resonant) frequencies

97
Q

Range of audible frequencies for the human bain

A

20-20,000 Hz

98
Q

Forced oscillation

A

Occurs when a periodically varying force is applied to a system. The system then drives at a frequency equal to the frequency of the force. Amplitude is greater when the force’s and system’s natural frequency are more similar (eg a child being pushed on a swing and pumping their legs)

99
Q

Resonanting

A

When the frequency of a periodic force and a natural frequency are equal. Amplitude is maximized

100
Q

Attenuation

A

Effect of friction on a system, which decreases the energy that a periodically varying force puts into the system. Results in finite amplitude of the system

101
Q

Equation for the speed of sound

A

v = sqrt(B/p)

B: bulk modulus, measures the medium’s resistance to compression
p: density of the medium

102
Q

Sound travels fastest through_____ and slowest through _____

A

solid with high density;

gas with low density

103
Q

Approximate speed of sound in air at 20* C:

A

343 m/s

104
Q

Infrasonic waves

A

Sounds with frequencies below 20 Hz

105
Q

Ultrasonic waves

A

Sounds with frequencies above 20000 Hz

106
Q

Doppler effect (def and equation)

A

Describes the difference between actual frequency and perceived frequency when the source of sound and the sound’s detector are in relative motion to each other.

f’ = f(v +/- v_d)/(v +/- v_s)

d for detector, s for source, v is the speed of the sound in the medium. Use + when the detector and source are moving closer together (results in higher perceived frequency)

107
Q

Shock waves

A

Created when an sound-producing object is traveling above the speed of sound, causing wavefronts to buildup at the the front of the object, actually compressing the medium. Passing of a shock wave results in a sonic boom

108
Q

Intensity (def, units, equation)

A

The average rate of energy transfer per unit area across a surface (or power per unit area). Units are Watts/m^2.

I = power / area

109
Q

How in intensity proportional to amplitude

A

Intensity is proportional to the square of the amplitude

110
Q

Sound level equation

A

beta = 10 * log (I / I_o)

I_o is the threshold of human hearing (1e-12 W/m^2)

111
Q

Calculation of a new sound after an old one has been changed in intensity by some factor

A

beta_f = beta_i + 10log(I_f / I_i)

112
Q

beat frequency

A

The magnitude of the difference in the frequencies of two sounds that are close in pitch

113
Q

How to measure wavelength on a standing wave:

A

It is twice the distance between two nodes.

114
Q

Equation of wavelength on a string

A

lambda = 2L/n

where n is the harmonic (a positive integer, corresponding to the number of half-wavelengths supported by the string)

115
Q

Equation for frequency of standing waves on a string fixed at both ends

A

f = nv / (2L)

116
Q

Fundamental frequency

A

The lowest frequency able to be supported in a given length of string/pipe. AKA the first harmonic

117
Q

On a fixed string, the harmonic is equal to the ____.

A

Number of antinodes

118
Q

First harmonic on strings/open pipe

A

The frequency at which half the wavelength is equal to the length of the pipe/string

119
Q

First harmonic of closed pipe

A

Frequency at which the only node is at the closed end and the only antinode is at the open end, so the length of the pipe is equal to 1/4 of the wavelength’

120
Q

Equation for wavelength in a closed pipe

A

lambda = 4L / n

n can only be odd integers

121
Q

Ultrasound machine

A

Machine using high frequencies to compare the relative densities of tissues in the body. Relies entirely on reflection. Calculates the distance traveled by the waves using the travel-time of the reflected waves

122
Q

Dielectric material

A

Another name for insulators

123
Q

Wavelengths, longest to shortest WL

A

radio, microwaves, infrared, visible light, UV, x-rays, gamma

also lowest to highest energy

124
Q

Electromagnetic waves are _____ because the oscillating electric and magnetic field vectors are _____ to the direction of propagation

A

transverse; perpendicular

also note that e and b field vectors are also perpendicular to each other

125
Q

All electromagnetic waves in a vacuum travel at _____, which is equal to _____m/s.

A

the speed of light; 3e8 m/s

126
Q

Wavelength range of visible light

A

400-700 nm (corresponds with violet to red visible light)

127
Q

Blackbody

A

An ideal absorber of all wavelengths of light

128
Q

Reflection

A

Rebounding ofo incident light waves at the boundary of a medium. The angle from the normal at which the light hits the boundary is equal in magnitude to the angle from the normal at which the light rebounds (on the other side of the normal)

129
Q

Real vs Virtual Images

A

Real: if the light actually converges at the position of the image

Virtual: light only appears to be coming from the position of the image, but does not actually converge there

130
Q

Plane mirrors

A

No convergence or divergence of light, so image is virtual. Can be conceptualized as spherical mirror with an infinite radius of curvature

131
Q

Concave

A

Looking at the inside of a spherical mirror. Convgerging mirror

132
Q

Convex

A

Looking at the outside of a sphere. Diverging mirrors

133
Q

Focal length

A

The distance between the focal point and the mirror.

For all spherical mirrors: f = r/s

Generally: 1/f = 1/o + 1/i + 2/r

o = distance between object and mirror, i = distance between mirror and image

134
Q

Magnification (def and meanings of positive and negative)

A

Dimensionless value that is the ratio of the image distance to the object distance:

m = i/o

Positive: upright image
Negative: inverted image

135
Q

Ray diagram

A

Approximates where an image is.

136
Q

A ray that passes through the focal point before reaching a convace mirror is….

A

reflected back parallel to the axis (the normal passing through the center of the mirror)

137
Q

A ray that strikes a concave mirror at the point of intersection with the axis is,,,

A

reflected back at the same angle measured from the normal

138
Q

Focal point

A

The point in space at which light hitting the mirror and traveling parallel to the principal axis will meet after reflection

139
Q

If an object is placed at the focal point of a concave mirror…

A

the reflected light rays are parallel to each other and no image is formed

140
Q

If an object is placed beyond F of a concave mirror…

A

the image is real, inverted, and magnified

141
Q

If an object is placed in front of the F of a concave mirror…

A

The image is virtual, upright, and magnified

142
Q

A single diverging image always forms a ____, _______, and ______ image, regardless of its position

A

Virtual, upright, and reduced

143
Q

Diverging mirror:

A ray that is parallel to the axis…..
A ray through the focal point…..
A ray to the center of the mirror…

A

parallel: reflects back through the focal point
through F: reflects back parallel to axis
to center of mirror: reflects back at same angle relative to normal

144
Q

Focal length of converging mirror is always ____, and ___ for diverging mirrors

A

converging: +f
diverging: -f

145
Q

Refraction

A

The bending of light as it passes from one medium to another and changes speed

146
Q

Snell’s law

A

The index of refraction of light in any medium besides a vacuum can be calculated as n:

n=c/v

c is the speed of light in air. v is the speed of light in the medium

n=1 in a vacuum

147
Q

When light enters a medium with a higher index of refraction, it bends _____ the normal

A

toward

148
Q

Cirtical angle

A

The incident angle at which the refracted angle equals 90 degrees

149
Q

Total internal reflection

A

All the light incident on a boundary is reflected back into the original material, results due to any angle of incidence greater than the critical angle. Occurs as the light moves from a medium with a higher refractive index to a medium with a lower one

150
Q

Lenses vs mirrors

A

Lenses refract light while mirror reflect it. Also, lenses have two surfaces that affect the light path: the surface of light entry and that of exit, whereas mirrors only have the one.

151
Q

Farsighted patients need ___ lenses, and nearsighted patients ____ lenses.

A

Converging (reading glasses)l diverging

152
Q

Lens equations for focal length and magnification

A

1/f = 1/o + 1/i

m = i/o

153
Q

Lensemaker’s equation

A

1/f = (n-1) (1/r1 = 1/r2)

where n is the index of refraction, r1 is the radius of curvature of the first surface and r2 of the second

154
Q

Real vs Virtual images regarding lenses

A

Real images are on the side of the lens opposite the light source. Virtual are on the same side as the light source

155
Q

Power of a lens

A

P = 1/f

Has the same sign as f, so power is positive for a converging lens and negative for a diverging lens.

Measured in diopters.

Sum up the power of lenses in series to find the total power

156
Q

Hyperopia

A

Farsightedness

157
Q

Myopia

A

Nearsightedness

158
Q

Equation for magnification (in total) of lenses in series:

A

m = m1 * m2 * …..* m_n

159
Q

Spherical aberration

A

The blurring of the periphery of an image as a result of inadequate reflection of parallel beams at the edge of a mirror or inadequate refraction of parallel beams at the edge of a lens.

Phenomenon: Real lenses’ perfectly rounded surfaces do not produce an image at a single point, but rather at a series of focal points

160
Q

Dispersion

A

The separation of various wavelengths of light. Different wavelengths lead to different decrees of refraction. Most common ex: splitting of white light into its component colors using a prism

161
Q

Chromatic aberration

A

Dispersive effect within a spherical lens. Depends on the thickness and curvature of a lens

162
Q

Diffraction

A

The spreading out of light as it passes through a narrow opening or around an obstacle. Proves as evidence for the wave theory of light

163
Q

As the slit through which light passes becomes narrowing, the central maximum becomes_____.

A

wider

164
Q

Equation for the location of dark fringes (minima) in slit-lens systems

A

asin theta = nlambda where a is the width of the slit and theta is the angle between the line drawn from the center of the lens to the dark fringe.

Note that bright fringes are halfway between dark fringes

165
Q

Interference of light waves (where do dark and bright fringes occur?)

A

Bright fringes occur when two light waves interact constructively. Dark fringes occur when two light waves interact desctructively

166
Q

Diffraction gratings

A

Have multiple slips arranged in patterns. Can create colorful patterns similar to a prism as different wavelengths interfere in characteristic patterns. Analagous to the organization of grooves on a CD or DVD. Ex: thin films like soap bubbles or oil puddles. Interference here is not between diffracted rays, but between reflected rays

167
Q

X-Ray diffraction

A

Uses the bending of light rays to create a model of molecules. Often used in combination with protein crystallography to analyze the structure of proteins

Determines the 3D molecular structure

168
Q

Plane-Polarized light

A

Light in which the electric fields of all the waves are parallel (oriented in the same direction)

169
Q

Circular Polarization

A

Rare. Results from the interaction of light with certain pigments or highly specialized filters. Circ-polarized light has uniform amplitude but continuously changing direction, which causes a helical orientation in teh propagating wave

170
Q

Photoelectric effect

A

When light of a sufficiently high frequency (blue to UV) is incident on a metal in a vacuum, the metal atoms emit electrons that produce a net charge flow per unit time (current). An “all or nothing phenomenon,” in that the frequency of light must be above the threshold, or else no current is produced

171
Q

Current

A

Net flow of charge per unti time

172
Q

Threshold frequency

A

The minimum frequency of light that causes ejection of electrons. The value depends on the type of metal being exposed to the radiation. Light with frequencies below this value do not have enough energy to dislodge an electron from the atom

173
Q

Equation for the energy of each photon

A

E = hf

h = Planck's constant = 6.626e-34 Js
f = the frequency of light
174
Q

Photon

A

Light quanta of which there is an integral number in each beam of light

175
Q

Equation for maximum kinetic energy of an ejected electron

A

KE_max = hf - W = hf - hf_threshold

where f_threshold is the frequency required to just barely free the electron

176
Q

IR Spectroscopy

A

Determines a chemical structure of interest because different bonds absorb different wavelengths of light

177
Q

UV-Vis Spectrocopy

A

Looks at the absorption of light in the visible and UV ranges.

178
Q

Fluorescence

A

Excitation of a fluorescent substance with UV light causes it to begin to glow with visible light because the particle had HIGH energy when excited by UV, and then returned to its original state in two or more steps. Dropping back down to the original energy level emits photons that are visible if in the visible-light frequency range

179
Q

Mass defect

A

The mass of every atom (except H) is slightly less than the summed masses of the protons and neutrons in the nucleus. Described by the equivalence of matter and energy: E = mc^2, in that the energy loss is due to the matter that has been converted to energy.

A small amount of mass translates into a HUGE amount of energy

180
Q

Strong nuclear force

A

The attractive forces that hold protons and neutrons together in the nucleus. Only acts over extremely short distances

181
Q

Binding energy

A

the fact that the bonded system is at a lower energy level than the unbonded constituents –> this energy must be radiated away in another form before the mass defect becomes apparent. This energy is binding energy –> Allows neutrons to bind together in the nucleus

182
Q

Atom with the highest binding energy (what does this imply)

A

Iron

Means that iron has the most stable nucleus

183
Q

Weak nuclear forces

A

Contributes to the stability of the nucleus

184
Q

The four fundamental forces of nature

A

Strong and weak nuclear forces, gravity, electrostatic forces

185
Q

A great amount of energy is released when small atoms ____ or large atoms ____.

A

Small atoms split

Large atoms combine

186
Q

Fusion

A

Small nuclei combining to form a larger one. Releases a huge amount of energy. Commonly occurs in stars to power themselves (fusing 2 H’s to form an He)

187
Q

Fission

A

Large nuclei splitting into smaller ones. Rarely spontaneous. Releases a large amount of energy. Chains of fission reactions commonly power nuclear power plants

188
Q

Alpha decay

A

An atom is converted to a new atom and an alpha particle, so the new atom has Z’ = Z-2, and mass A’ = A-2

189
Q

Beta- decay

A

A neutron is converted to a proton and a beta- particle, so the new atom has Z’ = Z+1 and A’=A

190
Q

Beta+ decay / Positron decay

A

A proton is converted to a neutron and a beta+ particle, so the new atom has Z’=Z-1 and A =A

191
Q

Electron capture

A

Can be thought of as reverse beta- decay.

Occurs in unstable nuclei. An inner electron is combined with a proton to form a neutron, so new atom can Z’=Z-1 and A’=A

192
Q

Exponential decay equation

A

rate of nuclear decay = -lambda * n

n = n_0e^(-lambdat)
where n_0 is the number of undecayed nuclei at time t=0

193
Q

gamma decay

A

No change in Z or A, just emission of a high-energy gamma ray

194
Q

The Hawthorne Effect

A

A change in behavior due to the knowledge that one is being observed

195
Q

Parameter

A

Information that is calculated using every person in a population

196
Q

Equipoise

A

In clinical research, it is becomes evident that one treatment is superior before the scheduled close of a study, then the trial must be stopped because it is clear that at least one of the groups is receiving inferior treatment (net harm)

197
Q

FINER Method in research

A

Method of evaluating a research question - determines whether the answer to one’s question will add to the body of scientific knowledge in a practical way. Asks five questions about:

Feasibility
Interest to other scientists
Novelty
Ethics
Relevance outside the scientific community
198
Q

Equation for the probability of independent events A and B happening simultaneously

A

prob_A * prob_B = prob_A+B

199
Q

As confidence level increases, width of the confidence interval ______

A

increases

200
Q

p-value

A

The probability of a significant difference/result of interest between two groups in the event that they are totally unrelated

201
Q

How to determine whether a data point is an outlier based on IQR:

A

If a low value is below Q1-(1.5)IQR or if a high value is above Q3+(1.5)IQR

202
Q

A dataset in which the median is much greater than the mean is skewed ______.

A

Left

203
Q

The area enclosed by the cardiac PV loop on a graph is…..

A

The work done

204
Q

Volumetric flow rate equation

A

Q = A*v

v is the velocity of the fluid in distance/s
Q is equal to cardiac output!

205
Q

Which group of blood vessels is the main source of peripheral resistance and why?

A

Arterioles because they experience the greatest pressure drop

This makes the arterioles the main regulators of blood pressure!

206
Q

Dispersion

A

The phenomenon of light separating into its colors. Different frequencies of light have different refraction indices (light of higher frequencies have higher refraction indices). This phenomenon explains chromatic aberration: images being blurry after light passes through a lens (higher refraction ==> blurrier image)

207
Q

Unit of Diopters

A

1 D = 1 m^-1

208
Q

How does one find focal length of a lens?

A

focal length is equal to the inverse of the strength of the lens, S, which is also described as the power of the lens.

f = 1/S - 1/ (1/o+1/i)

209
Q

Magnitude of the magnetic field produced by a current-carrying wire

A

B = muI / (2pi*r)

210
Q

Viscosity

A

Property of a fluid that characterizes the friction that opposes movement within the liquid itself. Energy put into a liquid during stirring disipates due to viscosity, explaining why it eventually stops flowing.

211
Q

Describe the change in potential energy as a rocket ship blasts off from the surface of the earth

A

Since the magnitude of PE_grav is always negative and inversely proportional to radius, it becomes less negative as the space ship blasts off from earth. Technically, PE is increasing and it must be due to a decrease in some other type of energy (ie it converts)

212
Q

Wave velocity equation

A

v = f*lambda

213
Q

Intensity

A

Energy per unit time per unit area (AKA Power per area)

214
Q

Adiabatic vs Isothermal

A

Adiabatic: There is no heat exchange between a system and its surroundings

Isothermal: The contents of the system remain at a constant temperature

215
Q

For resistors in parallel, their _____ are equal

A

Voltages (potential differences)

216
Q

The direction of a magnetic field is ___________ to an ion’s velocity and _________ to the magnetic force acting on the ion.

A

perpendicular; perpendicular

217
Q

Polarization is unique to _____ waves because only _____ waves can cause oscillations _____ to the direction of propagation.

Can sound be polarized?

A

Polarization is unique to transverse waves because only transverse waves can cause oscillations PERPENDICULAR to the direction of propagation.

Thus, sound CANNOT be polarized because the oscillations of particles due to sound are parallel to the direction of propagation, as sound is a longitudinal wave.

218
Q

Kinetic Molecular Model

A

Describes the macroscopic characteristics of gases. Applies to large number (N) of monoatomic ideal gas molecules in a rigid, closed container.

Total kinetic energy = N* 1/2 * m*v_avg^2

219
Q

Equation for average kinetic energy of individual gas molecule

A

KE_avg = 3/2 * kT

k: Boltzmann’s constant

220
Q

How to determine the color of the reflected light from the wavelength that is maximally absorbed?

A

The color that is reflected is the complement to the color that is maximally absorbed.

Complementary pairs:

  • Red, green
  • Orange, blue
  • Yellow, purple
221
Q

Potential energy of a capacitor

A

PE_c = 1/2CV^2

MCAT (6 decks)

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