Equations (by definition) Flashcards

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1
Q

Write out all three equations that use acceleration, velocity, and time.

A

vf = vi + at

(1/2)at2+ vit + ∆x

vf2 = vi2+ 2a(∆x)

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2
Q

What is the equation for the measurement of the gravitational force between two objects?

A

F = (Gm1m2) / r2

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3
Q

What equation measures torque?

And what are its units?

A

T = rFsinθ

Torque is unitless

r is the radius of the arm
F is the force
θ is the angle of force applied

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4
Q

What is the equation for rotational motion?

A

F = (mv2) / r

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5
Q

What is the general equation for power?

A

P = (W / t)

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6
Q

What is the general equation for work?

A

W = F d cos θ

F is the force applied
d is the displacement of the object
θ is the angle between the applied force and the displacement vector

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7
Q

What is the total mechanical energy equation?

A

E = U + K

U = potential energy

K = kinetic energy

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8
Q

What’s the equation for momentum?

A

p = mv

where m is mass and v is velocity

DO NOT confuse momentum and power

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9
Q

What are the three equations representing impulse?

A

I = F∆t
(where F is force and T is time)

I = ∆p
(where p is a change in momentum, not power)

I = mvf - mvi

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10
Q

What does it mean in a collision if “momentum is conserved” ?

A

It means that the momentum before the collision is the same as the momentum after the collision

pai + pbi = paf + pbf<br></br><br></br>This is sometimes called an “elastic collision”

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11
Q

What is a completely elastic collision?

A

A collision where total kinetic energy and total momentum are conserved (there was no energy lost to heat, light, or deformation), like two objects perfectly boucing off each other

(1/2)mavai2 + (1/2)mbvbi2 = (1/2)mavaf2 + (1/2)mbvbf2

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12
Q

What is an inelastic collision?

Do not confuse this with “comlpetely inelastic”

A

When two objects collide and move away from each other, and sound/light/heat/energy is released.

(1/2)mavai2 + (1/2)mbvbi2 > (1/2)mavaf2 + (1/2)mbvbf2

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13
Q

What is a completely inelastic collision, and what’s the best equation to represent it?

A

When two objects collide and stick to each other, rather than moving apart. Total kinetic energy is not conserved.

mavai + mbvbi = (ma + mb) vf

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14
Q

What is mechanical advantage? What equation can be used to represent it?

A

Mechanical advantage = (force in / force out)

It’s the ratio of the force exerted on an object by a simple machine to the force actually applied on the machine

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15
Q

What’s the conversion factor of Celsius to Kelvin?

A

K = C + 273

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16
Q

What’s the equation for the measurement of thermal expansion?

A

∆L = aL∆T

∆L is the change in length
L is the original length
∆T is the change in temperature
a is the expansion constant

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17
Q

What is the equation for thermal volume expansion?

A

∆V = BV∆T

Where ∆V is the change in volume
V is the original volume
∆T is the change in temperature
B is the volume constant (this is 3a if given the length constant)

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18
Q

What is the equation for specific heat?

A

Q = mc∆T = mc(Tf - Ti)

Where c is the specific heat
Q is in joules

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19
Q

A reaction is said to be isovolumetric.

What does that mean?

A

Isovolumetric means that it was held at a constant volume
∆U = Q

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20
Q

A reaction is said to be adiabatic.

What does that mean?

A

The reaction had no heat exchange.

∆U = -W

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21
Q

A reaction is said to be in a closed cycle.

What does that mean?

A

Also called isothermal, it means that the temperature of the reaction stays constant.

Q = W

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22
Q

What is an equation for measuring entropy?

A

∆S = Q / T

Q is heat gained or lost

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23
Q

What is specific gravity?

What’s an equation to find it if given the density of an object?

A

Specific gravity is a density ratio. It has no units.

If given the density of an object:

specific gravity = (density of object / density of water)

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24
Q

What’s the equation for pressure?

What is the SI unit?

A

pressure = (force / area)

SI unit is Pascal

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25
Q

What is absolute pressure?

What is the equation for absolute pressure?

A

Absolute pressure is the total pressure exerted on an object that’s submerged in fluid.

P = Po + pgh

P is the absolute pressure

Po is the pressure at the surface of the fluid
p is the density of the fluid, gh is gravity x height

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26
Q

What is gauge pressure?

What’s an equation to calculate gauge pressure?

A

Gauge pressure is the measurement of the pressure in an enclosed space that is above normal atmospheric pressure

Pg = P - Patm

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27
Q

What is Pascal’s Principle?

What are two equations associated with it?

A

When a change of pressure is applied to an enclosed fluid, the pressure change will be transmitted undiminished through all parts of the fluid and the containing walls of the vessel.

P = (F1 / A1) = (F2 / A2)

F2 = F1 (A2 / A1)

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28
Q

What is the equation for buoyant force?

A

Fbuoyant = (Vdisplaced fluid)(pfluid)g

Where p is density and g is gravity

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29
Q

A liquid is flowing through a pipe with openings of different size. What equation can find the fluid’s velocity?

A

This is the continuity equation

v1A1 = v2A2<br></br><br></br>Fluids flow faster through smaller cross sectional areas

30
Q

What is Coloumb’s Law?

What is its equation?

A

It gives the magnitude of electrostatic force between two charges:

F = k ( (q1q2) / r2)

Where k is the permitivity of free space constant

31
Q

What equation measures the electrostatic force between two charges?

A

Coulomb’s Law:

F = k ((q1q2) / r2)

32
Q

What are two equations for determining the magnitude of an electric field?

A

E = F / qo E = kq / r2<br></br><br></br>Where qo is the test charged placed in the field and F is the force it experiences<br></br><br></br>In the 2nd equation, q is the charge emitting the field

33
Q

What is the equation for the force experience by a charge when placed in an electric field?

A

F = qoE

34
Q

What is the equation for electric potential energy?

A

U = (kqQ) / r

Where q and Q are the two charges and r is the distance between them

35
Q

What is electric potential?

What is the equation to find it?

A

Electric potential and electric potential energy are very different things. Electric potential is the ratio of the magnitude of a charge’s electric potential energy to the magnitude of the charge itself

V = U / q

or V = k (Q/r)

36
Q

What is the equation for the measurement of current?

What is the SI unit of current?

A

i = (∆q / ∆t)

Ampere

37
Q

What is the equation for a magnetic field generated by current running through a straight wire?

A

B = (μo i ) / (2 π r )
μo is the constant 4π x 10-7

r is the distance from the wire

38
Q

What is the magnitude of a magnetic field generated by current moving through a loop of wire?

A

B = (μoi) / 2r

Where r is the radius of the loop of wire

39
Q

What is the equation for the force exerted on a moving charge as it passes through a magnetic field?

A

F = qvBsinƟ

q is the charge, v is its velocity, and Ɵ is the smallest angle between the charge velocity and the magnetic field vector

40
Q

What is the equation for the resistivity of a conductive material?

A

R = (p L ) / A

Where p is the resistivity constant, L is the length, and A is the cross sectional area

41
Q

If given the voltage drop and current across a resistor, what’s the equation to find energy dissapated?

A

P = iV

42
Q

If given the current and resistance across a resistor, what’s the equation to find the power disappated?

A

P = i2R

43
Q

What’s the equation for determining a capacitor’s capacitance from charge and voltage?

A

C = Q/V

44
Q

What’s the equation for the electric field inside a capacitor?

A

E = V/d

Where d is the distance between the plates

45
Q

What is the equation for the potential energy stored inside a capacitor?

A

U = (1/2)CV2

46
Q

What is Hooke’s Law?

A

Hooke’s law is the equation for the restoring force of a distended spring:

F = -kx

Where x is the displaced distance and k is the spring constant

47
Q

How do you calculate the acceleration of a displaced spring?

A

Angular momentum:

a = - ω2x

ω = 2πf = sqrt(k/m)

48
Q

A spring is compressed but not released. What is the equation for spring potential energy?

A

U = (1/2)kx2

49
Q

When a pendulum is swung away from its resting position, what equation shows its restoring force?

A

F = -mgsinθ

50
Q

What’s the equation for a standing wave and the length of an open pipe that supports it?

A

λ = 2L / n

Where L is the length of the pipe and N is a nonzero integer

51
Q

What is the equation for a closed pipe and the wavelength contained?

A

λ = ( 4L / n )

52
Q

In a mirror, what is the equation to calculate image distance?

A

(1/dobject) + (1/dimage) = (1/df)

53
Q

What’s the equation for finding the magnification of an object?

A

m = - (image size / object size)

54
Q

What’s the equation for finding the critical angle for total internal reflection?

A

sinθc = (n2 / n1)

55
Q

What’s the equation for locating the maxima of a slit interference pattern?

A

dsinθ = mλ

where m is a whole number refering to the maxima

56
Q

What’s the equation for locating the minima of a slit defraction pattern?

A

dsinθ = ( m + 1/2 ) λ

57
Q

What’s the equation for calculating the energy of a photon?

A

E = hf

Where h is Plank’s constant and f is the frequency

58
Q

What’s the equation to find the equilibrium constant?

A

Keq = [C]c[D]d / [A]a[B]b

59
Q

What’s the equation to find ∆G?

A

∆G = ∆H - T∆S

T is in Kelvin

∆G is Gibbs free energy

60
Q

Given ∆H and ∆S values, how can you tell if a reaction is spontaneous or non spontaneous?

A

If ∆H and ∆S are (-) then spontaneous only at low temps

If ∆H and ∆S are (+) then spontaneous only at high temps

If ∆H is + and ∆S is - then nonspontaneous

If ∆H is - and ∆S is + then always spontaneous

61
Q

What’s the equation to find stardard free energy change for a reaction?

A

∆Grxn = -RT ln Keq

62
Q

What are standard temperature and pressure?

A

273.13 K (0o C) and 1 atm

63
Q

One mole of a gas will take up _____ liters at STP

A

22.4

64
Q

What is Boyle’s Law?

A

At constant temperature, a gas’s volume is proportional to its pressure.

p1v1 = p2v2

65
Q

How do you find the partial pressure of a gas in a given gaseous mixture?

A

Partial pressure is the pressure of the gas multiplied by the mole ratio.

66
Q

What are colligative properties? How many are there?

A

Colligative properties are the physical aspects of solutions that are dependent on the concentration of dissolved particles.

They are:

  • vapor pressure depression
  • boiling point elevation
  • freezing point depression
  • osmotic pressure
67
Q

What’s the equation to calculate change in vapor pressure due to solute added?

A

∆P = XAPoA

XA is the mole ratio of solvent and Po is the vapor pressure of the pure solvent

68
Q

What’s the equation for boiling point elevation / freezing point depression due to the adding of a solute?

A

∆T = iKbm

m is molality, Kb is the constant for the solvent, and i is the Van’t Hoff factor

69
Q

What is the equation for solubility product constant?

A

For AxBy –> xA + yB

Ksp = [A]x[B]y

70
Q
A