Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Kaplan MCAT > Physics > Flashcards

Physics Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
0
Q

Unit of work and energy

A

Joule (J)

J = N m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Units for Newton (N)

A

s*s

(Kilogram, meters, seconds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Units of Joule (J)

A

s*s

(kgm^2)/s^2 = Nm = Pa*m^3

Kilogram * meter squared per second squared =
Newton * meter =
Pascals * meter cubed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Measure of Power (units of Power)

A

Watt (W)

W = J/s = N m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Units of Watt (W)

A

sss

(kgm^2)/s^3 = J/s = Nm/s

Kilograms * meters squared per seconds cubed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Electron-volt to Joule (J) conversion

A

1 eV = 1.6E-19 J

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Vectors vs. Scalars:

A

Vectors: have magnitude and direction.

Scalars: have magnitude only and no direction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Examples of Scalars:

A

Distance, speed, energy, pressure, and mass.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Splitting a Vector (V) into its X and Y components:

A

Draw a right triangle with V as the hypotenuse and angle (a).

X = V cos a

Y = V sin a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Method for subtracting vectors:

A

Flip the direction of the second vector then add as usual.

A - B = A + (-B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Definition of Friction:

A

Friction is a type of force that opposes the movement of objects. Friction forces almost always oppose an objects motion and cause it to slow down or become stationary. There are two types of friction: static and kinetic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Static Friction:

A

The friction that exists between a stationary object and the surface upon which it rests.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Equation for the gravitational force (F) between two objects:

A 
r*r

G: gravitational constant (6.67E-11)

m: two objects’ individual masses (in kilograms)
r: the distance between the two objects (in meters)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Kinetic Friction:

A

The friction that exists between a sliding object and the surface over which the object slides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Equation of magnitude for kinetic friction (fk):

A

fk = (uk)*N

fk: kinetic friction
uk: coefficient of static friction
N: the normal force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Definition of mass (m):

A

Mass is a measure of a body’s inertia - the amount of matter in the object. Mass is a scalar quantity, and as such, has magnitude only.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Definition of weight (Fg):

A

Weight is a measure of gravitational force (usually Earth’s) on an object’s mass. Because weight is a force, it is a vector quantity with the units of newtons (N).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Equation relating mass (m) and weight (F):

A

F = m*g

F: weight of the object

m: mass of the object
g: acceleration due to gravity (9.8 m/s*s, or 10)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Definition of acceleration (a):

A

Acceleration is the rate of change of velocity that an object experiences as a result of some applied force. Acceleration, like velocity, is a vector quantity. Acceleration in the direction opposite the initial velocity may be called deceleration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Newton’s First Law:

A

F = ma = 0

Also known as the law of inertia. It states that a body either at rest or in motion with constant velocity will remain that way unless a net force acts upon it.

F: net force acting on the object

m: mass of the object
a: acceleration of the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Newton’s Second Law:

A

F = ma

An object of mass (m) will accelerate (a) when the vector sum of the forces results in some nonzero resultant force (F) vector. No acceleration will occur when the vector sum of the forces results in a cancellation of those forces.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Newton’s Third Law:

A

Fab = -Fba

Also known as the law of action and reaction. To every action, there is always an opposed but equal reaction. The law states that for every force exerted by object A on object B, there is an equal but opposite force exerted by object B on object A.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The equations for Newton’s three laws of motion:

A
  1. F = ma = 0
  2. F = ma
  3. Fab = -Fba
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Formulas for dividing force vectors into its components on an incline plane:

A

F(parallel) = mgsin a

F(perpendicular) = mgcos a

Calculated with respect to the plane; parallel, and perpendicular to the plane that the object is resting on, and (a) the angle of the incline in degrees.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Equation that describes circular motion:

A

Fc = mvv/r

Fc: magnitude of the centripetal force

m: mass of the object
v: the speed (squared)
r: radius of the circular path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Equations for breaking up a net vector force (Fn) into it’s X and Y components:

A

Fx = Fn * cos a

Fy = Fn * sin a

Angle (a) is the measure in degrees from the horizontal X-axis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The first condition of equilibrium:

A

Translational equilibrium exists only when the vector sum of all the forces acting on an object is zero. This is a reiteration of Newton’s First Law. This means that the object will have constant velocity and constant speed (zero or not), but the acceleration will be zero.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The equation for Torque (t):

A

t = rF(sin a)

t: torque
r: length of the lever arm
F: magnitude of the force
a: angle between the lever arm and force vector

Torque depends not only on the magnitude of the force but also on the length of the lever arm and the angle at which the force is applied.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Second condition of Equilibrium:

A

Rotational equilibrium exists only when the vector sum of all the torques acting on an object is zero. This means that the object is rotating at some constant angular velocity or speed (which may or may not be zero).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Kinematics equation (no displacement):

A

v = v0 + at

v: velocity
v0: initial velocity
a: acceleration
t: time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Kinematics equation (no final velocity):

A

x = v0t + (at^2)/2

x: position
v0: initial velocity
t: time
a: acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Kinematics equation (no time):

A

v^2 = v0^2 + 2ax

v: velocity
v0: initial velocity
a: acceleration
x: position

32
Q

Kinematics equation (no acceleration):

A

x = vt

x: position
v: average velocity
t: time

33
Q

Equation for centripetal force (Fc):

A 
r
34
Q

What is energy:

A

The property of a system that enables it to do something or make something happen (the capacity to do work). The units for all energy is Joules (J).

35
Q

Types of Potential Energy:

A

Gravitational

Elastic potential

Electrical potential

Chemical potential

36
Q

Conservative forces:

A

Path independent and do not dissipate the mechanical energy of the system. Examples include gravity and electrostatic forces.

37
Q

Nonconservative forces:

A

Path dependent and cause dissipation of mechanical energy from a system. Total energy is conserved, but but some mechanical energy is lost as thermal or chemical energy. Examples include friction, air resistance, and viscous drag.

38
Q

What is work:

A

A process by which energy is transferred from one system to another.
W = Fd cos a = Joules (J)

39
Q

What is power:

A

The rate at which work is done or energy is transferred. Measured in units of Watts (W).

Power = Watts = dE/t = J/t

40
Q

Efficiency:

A

Work (in)

Dangle / Pull

41
Q

Equation for Kinetic Energy:

A

K = 1/2 m v^2

42
Q

Equation for gravitational potential energy:

A

U = m g h

43
Q

Equation for elastic potential energy:

A

U = 1/2 k x^2

44
Q

Equation for total mechanical energy:

A

E = U + K

45
Q

Equation for conservation of mechanical energy:

A

dE = dU + dK = 0

46
Q

Equation for (mechanical) work:

A

W = Fd cos a

47
Q

Equation for (gas-piston system) work:

A

W = P dV

48
Q

Equation for the definition of power:

A

P = W/t = dE/t

49
Q

Equation for the work-energy theorem:

A

Wnet = dK = Kf - Ki

50
Q

Equation for mechanical advantage:

A

MA = Fout / Fin

51
Q

Equation for efficiency:

A

Efficiency = Wout / Win =

load * load distance) / (effort * effort distance

52
Q

Zeroth Law of Thermodynamics:

A

Objects are in thermal equilibrium when they are at the same temperature; that is, they experience no net change of heat energy.

53
Q

Temperature:

A

Qualitatively, a measurement of how hot or cold an object is.

Quantitatively, related to the average kinetic energy of the particles that make up a substance.

54
Q

Thermal Expansion:

A

Describes how a substance changes in length or volume as a function of the change in temperature.

55
Q

Thermodynamic Systems vs. Surroundings:

A

The system is the portion of the universe that we are interested in observing.

The surroundings include everything that is not part of the system.

56
Q

Thermodynamic systems - isolated systems:

A

Do no exchange matter or energy with the surroundings.

E: A -x- S

M: A -x- S

57
Q

Thermodynamic systems - closed systems:

A

Exchange energy but not matter with the surroundings.

E: A – S

M: A -x- S

58
Q

Thermodynamic systems - open systems:

A

Exchange both energy and matter with their surroundings.

E: A – S

M: A – S

59
Q

State functions:

A

State functions are pathway independent and are not themselves defined by a process.

Pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, and entropy are all state functions.

60
Q

Process functions:

A

Process functions describe the pathway from one equilibrium state to another.

Work and heat are process functions.

61
Q

First Law of Thermodynamics:

A

The first law of thermodynamics is a statement of CONSERVATION OF ENERGY. That is, the total energy of the universe can never decrease or increase.

For a closed system, the total internal energy is equal to the heat flow into the system minus the work done by the system.

dU = Q - W

62
Q

Heat:

A

Heat is the process of energy transfer between two objects at different temperatures that occurs until the two objects come into thermal equilibrium (same temperature).

63
Q

Specific heat:

A

Specific heat is the amount of energy necessary to raise one gram of a substance by one degree Celsius or one unit Kelvin.

Specific heat of water is 1 cal/g*K

64
Q

Specific heat of water:

A

1 cal/g*K

65
Q

Heat of transformation:

A

During a phase change, heat energy causes changes in the particles’ potential energy and energy distribution (entropy), but not kinetic energy. Therefore there is no change in temperature.

66
Q

Isothermal process:

A

For isothermal processes, the temperature is constant (dT = 0), and the change in internal energy (dU) is therefore 0.

dU = 0

0 = Q - W (qU = Q - W)

Q = W

67
Q

Adiabatic process:

A

For adiabatic processes no heat is exchanged (Q = 0).

dU = Q - W
dU = 0 - W
dU = -W
68
Q

Isobaric process:

A

For isobaric process, the pressure is held constant (dP = 0).

69
Q

Isovolumetric (isochoric) process:

A

For isovolumetric (or isochoric) processes, the volume is held constant and the work done by or on the system is 0 (W = 0).

dU = Q - W
dU = Q - 0
dU = Q
70
Q

The Second Law of Thermodynamics:

A

The second law of thermodynamics states that in a closed system (up to and including the universe), energy will spontaneously and irreversibly go from being localized to being spread out (dispersed).

71
Q

Entropy:

A

Entropy is a measure of how much energy has spread out or how spread out energy has become.

On a statistical level, as the number of available microstates increases, the potential energy of a molecule is distributed over that larger number of microstates, increasing entropy.

Every NATURAL PROCESS is ultimately IRREVERSIBLE (like ice melting on a hot day). Under highly controlled conditions, certain equilibrium processes such as phase changes can be treated as essentially REVERSIBLE.

72
Q

Equation for thermal expansion:

A

dL = aL(dT)

dL: change in length
a: thermal expansion constant
L: starting length
dT: change in temperature

73
Q

Equation for volume expansion:

A

dV = BV(dT)

dV: change in volume
B: volume expansion constant (B=3a)
V: initial volume
dT: change in temperature

74
Q

Equation for first law of thermodynamics:

A

dU = Q - W

dU: change in internal energy
Q: energy transferred into the system as heat
W: work done by the system

75
Q

Equation for heat gained or lost (with temperature change):

A

q = mc(dT)

q: resultant heat
m: mass of the object
c: specific heat of the substance
dT: change in temperature

76
Q

Equation for heat gained or lost (at phase change):

A

q = mL

q: resultant heat
m: mass of the object
L: heat of transformation, or latent heat of the substance.

*dT is not used because there is no temperature change at the temperature of phase change. Temperature stays constant until the phase change is completed.

77
Q

Equation for Entropy (related to heat):

A

dS = Qrev / T

dS: change in entropy
Qrev: the heat gained or lost in a reversible process
T: temperature in Kelvin

units of entropy: J/mol*K

78
Q

Equation for the second law of thermodynamics:

A

dS(uni) = dS(sys) + dS(sur) > 0

dS(uni): change in entropy of the universe
dS(sys): change in entropy of the system
dS(sur): change in entropy of the surroundings

*the second law of thermodynamics states that the entropy change of the universe is always positive (increasing).

Kaplan MCAT (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions