Physics Flashcards
Formula for average speed
S = distance / time
Note: Involves NO Derivatives/Differentiation
Formula for average velocity
V = displacement(vector) / time
Note: Involves NO Derivatives/Differentiation
Formula for instantaneous speed
| Note: Involves NO Derivatives/Differentiation
V(instantaneous) |
Formula for instantaneous velocity
dx / dt
Formula for average accelaration
A = ΔV/ Δt
Note: Involves NO Derivatives/Differentiation
Formula for instantaneous acceleration
A = dV / dt
Formula for Jerk
Jerk = da / dt
Formula for Jounce
Jounce = d(Jerk) / dt
Is acceleration scalar or vector?
Either
Newton’s First Law
states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
Newton’s Second Law
a non-zero net force on an object causes acceleration
Newton’s Third Law
an action has an equal and opposite reaction
Unit of Newton
1 N = 1 kg.m/s^2
Unit of dyne
1 dyne = 1 g.cm/s^2
Unit of pound force
1 lb.f = 1 slug.ft/s^2
He stated that “ a falling object, regardless of mass will fall with constant acceleration”
Galileo Galilei
Universal gravitational constant
G = 6.67 x 10^-11 Nm^2 / kg^2
Centripetal acceleration formula
A = v^2 / R R = radius of motion
Centripetal force formula
F = m (v^2 / R ) R = radius of motion
Angular speed of a circular motion
w = 2 π f = v / R
It is force normal to circular path and is a real force
Centripetal Force
so called Imaginary Force
Centrifugal Force
Activity involving force and movement
Work
Is work a scalar or vector
Scalar
Formula for work
W = f · d · cos(θ) W = f · d W = ΔKE = - ΔPE KE = kinetic energy PE = Potential energy
Unit of erg
1 erg = 1 dyne.cm
Unit of pound foot
1 lb.ft = 1 lbf . ft
Rate of doing work
POWEEEEERRRRRR!
Formula of Power
P = W / t W = work
Is power a scalar or vector
Scalar
Unit of Watt
1 watt = 1 J/s = 1 N.m/s
Unit of horsepower
1 hp = 746 watts = 550 ft.lb / s
Capacity to do work
Energy
Is energy a scalar or vector
Scalar
Formula for kinetic energy
KE = 1/2 m·v^2
Formula for potential energy
PE = mgh
Formula for rotational kinetic energy
KE = 1/2 I x w^2 I = inertia w = angular velocity
Unit of Joule
1 J = 1 Nm = 1 kg.m^2/s^2
States that “energy is neither created nor destroyed in an Isolated system”
Law of conservation of energy
Formula for Law of conservation of energy
PEi + KEi + KE(rotational)i = PEf + KEf + KE(rotational)f
It is the amount of motion
Momentum
It is the change in momentum
Impulse
Is momentum scalar or vector
Vector
Is Impulse scalar or vector
Vector
Formula for Momentum
p = m · v (N.s)
Formula for Impulse
J = Δp = m·ΔV) = F· Δt p = momentum
the total momentum at all times is constant
Conservation of momentum
Formula for conservation of momentum
(m1·v1)i + (m2·v2)i = (m1·v1)f + (m2·v2)f
The kinetic energy and momentum is conserved
Elastic
when momentum is only conserve or energy is lost through heat, light, sound and etc
Inelastic
bodies merge after collision
Perfectly Inelastic
is the ratio of the final to initial velocity difference between two objects after they collide
Coefficient of restitution
Formula Coefficient of restitution
e = - (v2a - v2b) / (v1a - v1b) = sqrt(h(bounce)/h(initial))
If the coefficient of restitution is equal to 1
Perfect Elastic
If the coefficient of restitution is equal to 0
Perfect Inelastic
Formula for force on a spring
F =-kx
k=spring’s constant (N/m)
Formula for Period of mass on a spring
T = 2·π· sqrt(m/k)
k=spring’s constant (N/m)
Formula for angular velocity on a spring
w = sqrt(k/m)
Formula for period of the pendulum
T = 2·π·sqrt(L/g) L= length of the string g = gravity
Formula for period of Torsional pendulum
T = 2·π·sqrt( I / K )
I - Moment of Inertia
K - Torsional Constant
Wave Intensity of a mechanical wave
I = 2 · π^2 · v · ρ · f^2 · (Amplitude in meters)^2
Speed of propagation of a Transverse Wave
v = sqrt( T / (mu))
T - tension
(mu) - mass per unit length (kg / m)
Speed of propagation of a longitudinal wave
v = sqrt( E / (ρ))
E - Modulus of elasticity
(ρ) - density (Kg / m^3)
Modulus of elasticity(E) of Steel
E(steel) = 200GPa
A Mechanical wave where Propagation of the wave is parallel to the displacement of medium
Longitudinal Wave
A Mechanical wave where Propagation of the wave is perpendicular to the displacement of medium
Transverse Wave
Sound is a (Transverse/Longitudinal) Wave
Longitudinal
Speed of sound in Fluids (given Bulk Modulus and density)
v(fluid) = sqrt (β / ρ)
B - Bulk Modulus (in Pascals)
ρ - Density (in kg/m^3)
Speed of sound in Fluids (given pressure and density)
v(fluid) = sqrt (P·γ / ρ)
P - Pressure (in Pascals)
ρ - Density (in kg/m^3)
γ-Adiabatic Constant:
γ = 1.4 (diatomic)
γ = 1.67 (monoatomic)
Speed of sound in Fluids (given Temperature and Molar Mass)
v(fluid) = sqrt (γ·R·T / MM)
R - Universal Gas Constant (USE 8.314 J / Mol · K)
T - Temperature in Kelvin
MM - Molar mass
γ-Adiabatic Constant:
γ = 1.4 (diatomic)
γ = 1.67 (monoatomic)
Sound with a frequency below 20 Hz
Infrasound
Sound with a frequency above 20 KHz
Ultrasound
The energy Transferred per unit area and per unit time through sound
Sound Intensity
Lowest Intensity Perceptible to Human Ear
1 x 10^-12 W/m^2
another term for Lowest Intensity Perceptible to Human Ear
Threshold of Hearing
Formula for Sound intensity in dB
Intensity(dB) = 10 log ( (Intensity) / (1 x10^-12))
Threshold of Hearing in dB
0 dB
Intensity of Whisper in dB
20 dB
Intensity of Normal Conversation in dB
60 dB
Intensity of Street Traffic in dB
70 dB
Intensity of Large Orchestra in dB
100 dB
Intensity of Rock Concert in dB
110 dB
Intensity of Threshold of Pain in dB
130 dB
Intensity of Preforation of Eardrum in dB
160 dB
an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other
Doppler Effect
Formula for Doppler Effect
F(obs) =Fs · (V +- V(obs))/(V =- V(source))
V = Speed of sound
V(obs) = speed of observer
V(source) = speed of source
Formula of Speed of sound at a given temperature
V = 331 + 0.6 (T) T = temperature in Celcius
Mnemonic for Doppler Effect
OPT - Observer Positive Towards
SPA - Source Positive Away
is a formula used to describe the relationship between the angles of incidence and refraction
Snell’s Law
Formula for Snell’s Law
n1·sin(theta1) = n2·sin(theta2)
What property does not change when the velocity of a wave changes
Frequency
Index of Refraction Formula
n = c / v c = speed of light v = speed of medium
Range of visibility of a human
400 nm to 750 nm
Range of UV
below 400 nm
Range of IR
above 750 nm
What happens when light enters from a low index of refraction to a high index of refraction
light bends towards normal
What happens when light enters from a high index of refraction to a low index of refraction
light bends away normal
angle of incident ray that causes 90 degrees refraction angle
Critical Angle
Index refraction of water
n = 1.33
Index refraction of glass
n = 1.5
Amount of visible radiation passing per unit of time
Luminous Flux
SI unit of flux emitted by a point source of 1 candela through an angle of 1 steradian
Lumen
the solid angle that subtends an area of a surface on a sphere equal to r^2
Steradian
Formula for luminous flux
F(lumen) = I(candela) · w(steradian)
Formula for total luminous flux
F = 4·π · I(candela)
Solid angle of an entire sphere
4·π Steradians
Luminous Flux is analogous to
Magnetic Flux
Luminous flux per unit area expressed in lux
Illuminance (lumens/sq. ft)
Formula for Illuminance (E)
E = F(lumen) / Area E = (I(candela) / d^2)·cos(theta)
Luminous intensity per unit area
Luminance ( cd/ m^2 )
Formula for Luminance
B = I(candela) / Area
The image formed by a Plane Mirror is (Virtual/Real, Upright/Inverted, Left-Right Retained/Left-Right reversal, Same/Different Size, Same/Not Same Distance)?
- Virtual
- Upright
- Left-Right Reversal
- Same Size
- Same Distance
A Convex mirror is (Converging/Diverging)?
Diverging (-f)
A Concave mirror is (Converging/Diverging)?
Converging (+f)
The image formed by a Concave mirror when the object is BEYOND the focal point is (Virtual/Real, Upright/Inverted, Magnified/Unmagnified)?
- Real
- Inverted
- Unmagnified
The image formed by a Concave mirror when the object is AT the focal point is (Virtual/Real, Upright/Inverted, Magnified/Unmagnified)?
No Image
The image formed by a Concave mirror when the object is WITHIN the focal point is (Virtual/Real, Upright/Inverted, Magnified/Unmagnified)?
- Virtual
- Upright
- Magnified
The Object Distance (p) for the Mirror/Lens Equation is Always (Positive/Negative)
Positive
The sign of Image Distance (q) for the Mirror/Lens Equation when the Image is Real
Positive
The sign of Image Distance (q) for the Mirror/Lens Equation when the Image is Virtual
Negative
The sign of Focal length (f) for the Mirror/Lens Equation when a Mirror/Lens is Converging
Positive
The sign of Focal length (f) for the Mirror/Lens Equation when a Mirror/Lens is Diverging
Negative
Formula for Focal Length
f = focal length = (Radius of curvature of lens/mirror) / 2
Formula for the Mirror/Lens Equation
1/f = 1/p +1/q f = focal length = (Radius of curvature of lens/mirror) / 2 p = Object Distance q = image Distance
Formula for Magnification (m)
m = -(Image Height) / (Object Height)
Sign of Magnification (m) if image is upright with respect to the object
Positive
Sign of Magnification if image is Inverted with respect to the object
Negative
For Mirrors, Location of Image with respect to the observing object when image is REAL
Image and object are located at the same side of a mirror
For Mirrors, Location of Image with respect to the observing object when image is VIRTUAL
The image and object are located at Opposing sides of the mirror
The Image Formed by a Convex Mirror is always (Virtual/Real, Upright/Inverted, Bigger/Smaller)
- Virtual
- Upright
- Smaller Image
FOR BOTH MIRROR AND LENS:
If an Image is (Upright/Inverted), it is also a (Virtual/Real) Image. What two Confgurations of this statement are always true?
- Upright And Virtual
- Real And Inverted
A Convex lens is (Converging/Diverging)?
Converging (+f)
A Concave lens is (Converging/Diverging)?
Diverging (-f)
Are the magnitude and Focal Length formulas for mirrors apliccable to lenses as well?
yasssssssssss
The image formed by a Convex Lens (Increases/Decreases) in Image height when the object BEYOND a point that is twice the distance of the focal point (2f) approaches that point
Increases
When the object is at a point that is twice the distance of the focal point (2f), The image formed by a Convex Lens has an Image height that is equal to?
Image Height = Object Height
The image formed by a Convex Lens (Increases/Decreases) in Image height when the object BETWEEN a point that is twice the distance of the focal point (2f) and the focal point (f), approaches the focal point (f)
Increases (Approaches infinity)
When the object is at the focal point (f), The image formed by a Convex Lens is ______?
Non-existent (No image is formed)
The image formed by a Convex lens when the object is WITHIN the focal point is (Virtual/Real, Upright/Inverted, Magnified/Unmagnified, Same-Side/Opposite Side of object)?
- Virtual
- Upright
- Magnified
- Same Side of Object
Formula for the Strength of Lens (P)
P = 1 / (+-f) f = Focal Length (in Meters)
Formula for the Strength of Lens (P) when more than one lens is used
P(total) = P1 +P2 + …
Formula for the Lensmaker Equation
1/f = (n - 1) [1 / ( +- R1) + 1 / ( +- R2)]
f - focal length of compounded lens
n - Index of Refraction of material used
R1 & R2 -Radii of lenses
Lensmaker Equation: R1 and R2 Sign Convention
R1 and R2 are individually evaluated:
POSITIVE if Lens of that specific R is convex
NEGATIVE if Lens of that specific R is concave
A Concave lens always has an (Upright/Inverted , Real/Virtual) Image
- Upright
- Virtual
Property of lenses that is opposite in a mirror
Answer:
The Convention Of whether the image is Virtual or Real
It is based on:
if the Image and Object is on the same side of the LENS, the image is VIRTUAL
if the Image and Object is on opposing sides of the LENS, the Image is REAL
As opposed to a mirror:
if the Image and Object is on the same side of the MIRROR, the image is REAL
if the Image and Object is on opposing sides of the MIRROR, the Image is VIRTUAL
Does the sign of a virtual or real image distance remain the same for both mirrors and lenses?
YASSSSSSSSSSSSSSSSSS
(q) - is the image distance
q is always positive when real image
q is always negative when virtual image
The Ratio of a fluid’s Density Compared to ρwater @ 4 Celcius
Specific Gravity
Specific Gravity of Air
0.0013 Unitless
Specific Gravity of Copper
8.79 Unitless
Another term for Specific Gravity
Relative Gravity
Formula for Specific Gravity
SG = (ρ liquid) / (ρ water)
The reciprocal of Density
Specific Volume
Formula for Specific Volume
SV = 1 / ρ = V /m
V - Volume
m - mass
The product of Density and the gravitational constant (g)
Specific Weight γ
Formula for Specific Weight γ
SW(γ) = ρ g (in N/m^3)
a property analogous to the modulus of elasticity, but is for fluids
Bulk Modulus (unit in Pa)
the Reciprocal of the Bulk Modulus
Compressibility ( unit in 1/kPa)
A perpendicular force per unit area of a fluid exerted on a surface of an object, in which the object displaces a volume of that fluid
Pressure
Formula for Pressure of a Submerged object in a fluid
P(submerge) = P(@surface of fluid) + ρ(g)(d)
g - gravitational acceleration
d - distance of submersion of an object with respect to the fluid surface
ρ-density of object, not the fluid
Formula for Gauge Pressure
P(gauge) = P(absolute) - P(atmosphere)
A device that measures the difference in pressure
Manometer
A device that measures atmospheric pressure
Barometer
The set of laws that dictate the planetary motions of the solar system in 1600s
Kepler’s Laws of Planetary Motion
Kepler’s First Law
(Law of Ellipses)
Planets move in ellipses, with the sun as a common focus
Kepler’s Second Law
(Law of Equal Areas)
A Line from a planet to the sun sweeps over an equal amount of area in equal increments of time
Kepler’s Third Law
(Law of Harmonics)
(Period)^2 is proportional to (mean distance to the sun)^3
Orbital Speed of the Earth
30 Km / s
1 atm converted into:
Pa mmHg Torr Bar PSI (lb/in^2)
1 atm is equal to:
101325 Pa 760 mmHg 760 Torr 1.013 Bar 14.7 PSI (lb/in^2)
