Download Amplitude (symbol: A)

◆Amplitude (symbol: A)
The maximum displacement of a vibration or oscillation, measured from the position of
equilibrium.
◆Period (symbol: T, unit: s)
Period is the interval of the time between successive occurrences of the same state in a
wave.
※the inverse of the period is the frequency(f).
f 
1
T
◆Frequency (symbol: f, unit Hz)
Frequency is the rate per second of a pattern of motion repeats itself at any single
point.
◆Transverse and longitudinal wave
Transverse wave, the motion of particles in the medium is perpendicular to direction of
propagation of wave, whereas longitudinal wave (the motion of particle in the medium)
is along the same line as the direction of the propagation of wave.
◆Intensity (symbol: I, unit: W/㎡)
Intensity is a measure of the average power per unit of area carried by wave past a
surface perpendicular to the wave’s direction of propagation.
◆Sound level
⇒終わってない
◆Angle of incidence
It is an angle between the propagation directions the incident wave and the normal
that of the direction is perpendicular to the boundary between medium and another.
◆Angle of reflection
Angle of reflection is angles between the propagation direction of a reflected wave and
the normal that of the direction is perpendicular to the boundary between medium and
another.
◆Angle of refraction
Angle of refraction is angles between the propagation direction of a transmit wave,
which travels in different propagation direction of incident wave, and normal that of the
direction is perpendicular to the boundary between medium and another.
◆The index of refraction (symbol: n, unit:－)
It is a ratio of the velocity of light in a vacuum to its velocity in a specified medium
◆Magnification
⇒ 終わってない
◆Object distance
⇒ Lens formula
◆Image distance ⇒ Lens formula
◆Focal length
The focal length is a distance between the center of lens and its focus point. Focal
length expresses a measure of how strongly lens converges or diverges light. A shorter
focal length has greater optical power than one with a long focal length.
◆Converging lens
Converging lens ,such as Biconvex, Plano-convex, have a property that parallel beam
of light traveling parallel to the lens axis and passing through the lens will be converge
to a spot on the axis, at focal length behind the lens. In thus case, the lens called a
converging lens.
◆Diverging lens
Diverging lens, such as Biconcave, Plano-concave, have a property that parallel beam
of light traveling parallel to the lens axis and passing through the lens will be diverged.
In thus case, the lens called a diverging lens.
◆Diopter(symbol: d, unit:－)
Diopter is a non-SI unit of measurement of the optical of a lens, which is equal to the
reciprocal of the focal length measured in meter.
Ex) 3 diopter lens bring parallel ray of light to focus at 1/3 (m)
d 
1
f
→
◆Electric Field (symbol: E, unit; N/C)
The space surrounding an electric charge has a property called an electric field. This
electric field exerts a force on other charged object. Electric field is defined as the
electric force per unit charge of particle.


E
FE
q
※ The direction of field is taking to be the direction of the force it would exert on a
positive test charge.
◆Potential difference (symbol:
⊿V
unit J/C, V)
Potential difference is the change in *electric potential energy per unit charge.
V 
U
q
*electric potential energy(UE) ⇒ A function of the position of moveable charge (q).
◆Electric volt (symbol: eV, unit: eV)
Electric volt is a unit of energy that a particle with charge ±e(such as an electron or
proton) gains, when it is accelerated through a potential difference of magnitude 1V.
Cf.
From 1(V) = 1(J/C) and e = 1.60×10－19 (C)
⇒ 1(eV) = e×1(V) = 1.60×10－19 (C) × 1(J/C)
= 1.60×10－19 (J)
That is to say……. 1(eV) = 1.60×10－19 (J)
◆Electric current resistance(symbol:Ω, unit: Ω)
Electric current resistance is a resistor or other circuit component which opposes the
passage of an electric current. It could be described that the ratio of the potential
difference (⊿V) across a conductor to the current (I) through the material.
◆Coulomb’s law (P570)
Coulomb’s law give the magnitude of electrostatic force between two point charges that
is directly proportional to the magnitudes of each charge and inversely proportional to
the square of the distance between the charges.
〔Coulomb’s law〕
F  Kc
q1 q 2
r2
→Kc could be described K also.
Kc = 8.988×109 Nm2/C2 ,→ coulomb constant or electrostatic constant
F: is the magnitude of the force exerted
q: is the charge on body
r: is the distance between 2 particles(charge on body)
◆Law of reflection
Law of reflection said that the angle of incidence(θi) equals the angle of reflection(θr),
and the incident ray, reflected ray, and the normal all lie in the same plane.
〔Law of reflection〕
the angle of incidence(θi)
normal
incidence
the angle of reflection(θr)
reflected
θi
θr
⇒
θi = θr
◆The law of refraction
The law of refraction is a formula to described the relationship between the angle of
incidence ray and refraction ray.
The law said that the ratio of the sin of the angle of incidence(θi) and refraction (θt)is
a constant that depend on media, and the incident ray, transmitted ray, and the normal
all lie in the same plane.
〔The law of refraction〕
Incidence
normal
That is to say….
θi
boundary
ni sin i  nt sin t
θt
transmitted
◆Ohm’s law
Ohm’s law state that the current(I) passing through a conductor, from one terminal
point on the conductor to another terminal point of conductor, is directory proportional
to the potential difference(⊿V) (and inversely proportional to the resistance(R)).
〔Ohm’s law〕
I:
R:
⊿V
current
⇒
I  V
⇒
I 
resistance
: potential difference
V
R
◆Lens formula
Lens formula expresses the relationship of object distance, image distance and focal
length. The sum of the inverse of image distance and the inverse of image distance is
equal to the inverse of focal length.
〔Lens formula〕
p: object distance
1
1
1


f
p
q
q: image distance
f: focal length
lens
object
focal point
f
image
p
q
※問題集では object distance と image distance を、それぞれ o と i で表記してあります。