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Conceptual Physics: Form WSF.0.0A
Name ______________________________
FORMULAS
Date _________________ Period _____
Metric Prefixes
103
102
101
1
10–1
10–2
10–3
10–4
10–5
10–6
10–7
10–8
k
–
–
none
d
c
m
–
–
µ
–
–
10–9 10–10 10–11 10–12
n
–
–
Motion
Speed:
d
t
distance: d = vt
d
time: t =
v
speed: v
=
• v = speed
• d = distance
• t = time
Acceleration:
acceleration: a =
time: t =
∆v v f − v i
=
t
t
v f − vi
a
final velocity: v f = vi + at
• a = acceleration
• ∆v = change in velocity
v f = final velocity
vi = initial velocity
Free Fall: (objects accelerating because of gravity)
final speed: vf = gt + vi
distance: d = ½at 2 + vit
v avg =
v f + vi
2
•
•
•
•
g = a = 9.8 m/s² = acceleration of gravity
d = distance
• t = time
• vf = final speed
vi = initial speed
vavg = average speed
Units:
distance:
time:
mass:
m = meters; km = kilometers; cm = centimeters
h = hours; s = seconds
g = grams; kg = kilograms
Energy
Gravitational Energy
PE = mgh
KE = ½mv2
• The height from which the object falls (h)
• The mass of the object (m)
• The acceleration of gravity (g)
• The mass of the object (m)
• The speed (v)
p
Conceptual Physics: Form WSF.0.0A
Formulas
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Page 2
Force
Net Force:
• Forces in the same direction
• Fnet = net force
Fnet = F1 + F2 + . . . + Fn
• F1 + F2 + . . . + Fn = add all the forces
•
•
Forces in opposite directions
Fnet = FL – FS
• FL = larger force
• FS = smaller force
• FL – FS = subtract the forces
Forces at right angles
Pythagorean theorem
a2 + b2 = c2
c = c2
•
THE NET FORCE IS IN THE
DIRECTION OF THE
LARGER FORCE
• a = one of the forces at right angles
• b = one of the forces at right angles
• c = the net force
Multiple forces
Always add all the forces acting in the same direction before subtracting or applying the Pythagorean
theorem
Newton's Second Law of Motion:
F
m
force: F = ma ( F = m × a )
accleration: a =
mass: m =
F
a
• a = acceleration
• F = force
• m = mass
Air Resistance:
Fnet = Fweight − Fair resistance
• Fnet = net force
•
m = mass
Fweight = mg
• Fweight = weight
• Fair resistance = air resistance
•
g = acceleration of gravity (9.8m/s²)
Units:
distance: m = meters; km = kilometers; cm = centimeters
time:
h = hours; s = seconds
mass:
g = grams; kg = kilograms
kg • m
1N = 1 2
force:
N = newtons;
s
Conceptual Physics: Form WSF.0.0A
Formulas
FORMULAS
Page 3
Machines
Work:
W=F×d
•
•
•
W = work (J)
F = force (N)
d = distance (m)
Power:
Power =
P=
Work
time
W
t
Mechanical Advantage:
mechanical = output force
advantage
input force
F
MA = out
Fin
Efficiency:
efficiency =
eff =
work output
× 100%
work input
Wout
× 100%
Win
(NOTE: Express efficiency as a decimal to calculate Wout or Win.)
Inclined Plane:
Wout = Fout × Dout
Win = Fin × Din
Wf = Win – Wout
AMA = Fout/Fin
IMA = Din/Dout
Eff = (Wout/Win) × 100
Eff = (AMA/IMA) × 100
Conceptual Physics: Form WSF.0.0A
Formulas
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Machines (Continued)
Levers:
AE
AR
M =F×A
• IMA = ideal mechanical advantage
• AE = effort arm
M = M 1 + M 2 +...
Balanced levers
• M E = effort moment
• M R = resistance moment
IMA =
ME = MR
• AR = resistance arm
Wheel and Axle:
IMA =
input radius
output radius
IMA =
Rin
Rout
Pulleys:
IMA = # of supporting strands
IMA (fixed pulley) = 1
IMA (movable pulley) = 2
Units:
work:
power:
MA:
J = joules
W = watts
no units
(also units for energy)
1 W = 1 J /s
Conceptual Physics: Form WSF.0.0A
Formulas
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Momentum
Momentum:
p = mv
C p = momentum (kg·m/s)
C m = mass (kg)
C v = velocity (m/s)
pTOTAL = p1 + p2 + . . . + pn
Change of Momentum and Force:
Definitions
Substitutions
• F = ma
∆v
t
• ∆p = m∆v
• a=
m∆v
t
∆p
F=
t
F=
Waves
Speed:
v=fλ
C v = speed (m/s)
C f = frequency (1/s or Hz)
C λ = wavelength (m)
C pTOTAL = total momentum
C p1, p2, pn = momentums
of the objects in a system
Conceptual Physics: Form WSF.0.0A
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Sound
M=
v
v sound
C M = mach number
C v = speed relative to the medium
C vsound = speed of sound in the medium
Speed of Sound Through Different Materials
Material
Speed (m/s)
Air
343
Water
1,483
Steel
5,940
Glass
5,640
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Light
Primary Colors
Speed in a vacuum
Speed in a vacuum = 3.0 × 108 m/s
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Heat
Temperature:
K = C + 273
C K = Kelvins
C = K – 273
C C = Celsius (EC)
Heat:
q = mCΔT
C q = heat (joules)
ΔT = Tf – Ti
 J
J 
or
C C = specific heat 

gK 
 g° C
C ΔT = temperature change
C Tf = final temperature
C Ti = initial temperature
Specific Heats of Common Substances:
Units:
heat
temperature
specific heat
Material
Specific Heat (J/g°C)
water
4.18
aluminum
0.897
copper
0.385
lead
0.129
nickel
0.444
zinc
0.388
J = joules
EC = degrees Celsius; K = Kelvins
J
J
= joules per gram degree Celsius or joules per gram Kelvin
or
g° C
gK
Conceptual Physics: Form WSF.0.0A
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Pressure and Fluids
Pressure:
F
A
force: F = PA ( F = P × A)
pressure: P =
area: A =
F
P
Archimedes' Principle:
m
V
mass: m = D × V
m
volume: V =
D
V = L ×W × H
(NOTE: Density of water – 1 g/mL
density: D =
Pascal’s Principle:
F1 F2
=
A1 A2
• P = pressure
• F = force
• A = area
• D = density
• m = mass
• V = volume
• L = length
• W = width
• H = height
or 1 kg/L )
• F1 = force applied on surface one
• F2 = force applied on surface two
• A1 = area of surface one
• A2 = area of surface two
Units:
force:
N = newtons;
1N = 1
kg • m
s2
pressure: Pa = pascals
area:
m2 = meters squared
volume: m3 = meters cubed; cm3 = centimeters cubed (note: 1 mL = 1 cm3); L = liters
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