Summary Physics notes 1

Physics

,Measurements and their errors
Always write in standard
form Precision is how close together repeated measurements
to allow other
significant figures to are to each &




be shown .
-




Accuracy is the closeness a measurement is to the true value
a
Systematic continuous trend
-



↓ .
error is an error
of
a


This is due to your accuracy -
a random error has no trend .




of yourfinal answer which
should be to the smallest
significant figure value in * half the instrument resolution (or wholeresolutiona
the question
M
*
.




/half the range of your repeat
The absolute uncertainty the interval
-




is results.
within which the true value can be

expected to lie. when adding subtracting values : add the uncertainty

When multiplying dividing Values : add the P Uncertainty
calculated value- true value
%0
difference
X100
= true Value


Instrument resolution is the Smallest scale an

certainty X
No uncertainty
100
mean value instrument can measure .




If there is a
power You
.




multiply by the power .




i readfirst

Learn the Slunits and :
prefixes

mass(kg) , length (n) time(s)
, ,
a mount of Substance

temperature(2) current(s)
,

-
Pregites +, G, M
:
, 1
,
c 2
, , 1, v P, f
see which line
watchesaa b
,


above.

, Waves Progressive transfer energy transferring
waves : without material




Wavelength-distance between the same points on two consecutive Waves .

c= 5) + wavelength
Amplitude-distance from equilibrium line to the maximum displacement ,
↓
Frequency - the number of waves that pass single point per second a .
wave frequency
speed
Period - Time taken for a whole wave to completely pass a
Single point I
medium a
substance/material that transmits a waves period =
energy
-




frequency
(T)
(6)


Transverse waves :
Longitudinal waves :

Oscillation of particles at right angles to the Oscillation of particles Parallel to the
direction of
energy transfer direction o
energy transfer
e EM travel at 3x108ms" in e sound >
requires medium
-
vacuum .
g
-
a
g
.
a
waves
.
. .




They have a trough They have
and peak .
compressions and rarefactions .
displacement

IIIIIIIIIIIIIII/III
2
I replie
a
either
time or position
or time period
Phase :
EM waves have both electric and The position of a
point on
certain a wave
cycle
magnetic fields at
right angles Phase Difference : How muchar a
particle wave lags behind another .




to each other .
Electric is usually Amplitude does not matter
Only shown .
-
Ensure you know each Two points are
completely out of phase When they are an odd integer of
wavelength name half cycles apart This . is is or 1800
Phase is
usually measured in radians .




Polarisation : (note :
only possible for transverse)

A
an unpolarised
these oscillations
wave


are in
is where

all Orientations
complex
Problem
*
7 An unpolarised light wave enters T.A. 1.
TA
.




↑
-




a The wave then passes through T.A. 2 which is rotating slowly. Plot
ve
a
plane polarised wave is one where the light intensity released visible from after T.A. 2.
these oscillations are in one orientations

(cos()
13
TA
. .
=
Transmission axis
=

T A x-axis
- . .




un Material dispersion
is due to
different As I cose light interity at point
optics
=




7
- Wavelengths having different and
light intensity cannot be negative ,




speeds due to different
1

refractive indices in the core. modal dispersion is the
refractive glass
index of core
>
prevents
- cladding Change in the
different paths
must be higher than cladding. the light takes
L Crosstalk' where along thefibre
Wave
↓ light would enter other from side
Problem , cora must vibres m
be also
narrow to reduce use single wavelength to stop
possible paths for light to take the wavelengths dispersing slightly 111111111
wave from top