i Course Outline: Physics 11 Ms. Johnston (Rm. 106N) Students will demonstrate an understanding and appreciation of the role of physics in society and develop knowledge, skills and methods employed by physicists. Emphasis will be placed on the applications of physics to everyday living and the skills needed in the workplace. Students will be engaged in the investigation of scientific questions and the development of plausible solutions. Course Content Section 1 - Introduction to Physics Measurements of Science Degree of Uncertainty Displaying Data Manipulating Equations Section 2 - Kinematics and Dynamics Describing Motion: Velocity Acceleration Forces Vectors Motion in Two Directions Universal Gravitation Momentum and Its Conservation Section 3 - Mechanical and Heat Energy Work, Energy and Power Energy Thermal Energy Section 4 - Wave Motion and Geometric Optics Waves and Energy Transfer Light Reflection and Refraction Mirrors and Lenses Diffraction and Interference of Light Section 5/6 - Nuclear Physics/Special Relativity Supplies 3 ring binder pencil and pen graph paper (4mm) calculator ruler protractor
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3. How much heat is absorbed by 60.0 g of copper when it is heated from 20.0oC to
80.0oC?
(1.39x103J)
4. A 38 kg block of lead is heated from -26 oC to 180 oC. How much heat does it absorb
during the heating? (1.0x106J)
5. The cooling system of a car engine contains 20.0 L of water (1 L of water has a mass
of 1kg). What is the change in the temperature of the water if the engine operates
until 836.0 kJ of heat are added? (10.0oC)
6. A 5.00x102 g block of metal absorbs 5016 J of heat when its temperature changes
from 20.0oC to 30.0oC. Calculate the specific heat of the metal. (1.00x103 J/kgK)
7. A 565g cube of iron is cooled from the temperature of boiling water to room
temperature (20oC).
a. How much heat must be absorbed by the cube? (2.0x104 J)
b. If the iron is cooled by dunking it into water at 0oC that rises in temperature
to 20oC, how much water is needed? (0.24kg)
Chapter 5: Energy 96
5.5 Efficiency
Law of Conservation of Energy: the amount of energy present _________
an energy transformation is equal to the amount of energy present
_________ the energy transformation.
However, some of the energy in a transformation is not a _________ form of
energy and is _________.
Efficiency = Energy output x 100
Energy input
_________ - the ability of a device to convert energy
Energy _________– useful energy produced by a converter (J)
Energy _________ – energy consumed by the converter (J)
Converter Input energy Output energy
Car engine _________ _________
(gasoline) (motion)
Ex#1: An internal combustion engine burns 1200J of chemical energy. The
fuel is vaporized, producing very high pressures that push down on the pistons
which turn the crankshaft, thus turning the wheels. In the end, only 100 J of
mechanical energy is produced to move the car forward. What is the
efficiency of the car’s engine?
Ex#2:A 1200 W electric kettle is used for 10 minutes.
a) How much energy does it require?
b) If 6.0 x 105 J of energy is transferred to the water in the kettle, what is
its efficiency?
Chapter 5: Energy 97
Efficiency
1. How much electrical energy does a 1200 W electric kettle use in each of the
following times?
a. 1.0 s_________
b. 1.0 min _________
c. 1.0 h _________
d. 1.0 day _________
2. How much heat energy does it take to heat 2.0 kg of water from 10oC to 100oC?
3. How long would it take a 1000 W kettle to do the job described in question 2,
assuming that it is 100% efficient?
4. Several friends use a simple rope and pulley to raise a tree house from the ground
into a tree. The mass of the tree house is 150 kg. By pulling together, the friends
manage exert an average force of 1.6 x 103 N as they raise the tree house a distance
of 3.2 m above the ground.
a) How much work did the friends actually do to raise the tree house?
b) How much “useful” work was done?
c) What is the efficiency of the rope and pulley in raising the treehouse?
d) Suggest why the efficiency of this simple machine is not 100%.
Chapter 5: Energy 98
5. A container factory uses a 370 W motor to operate a conveyor belt that lifts
containers from one floor to another. To raise 250 1-kg containers a vertical
distance of 3.6 m, the motor runs for 45 s.
a) Determine the useful energy output.
b) How much energy does the motor use?
c) What is the efficiency of the motorized conveyor system?
6. A 60 kg mountain climber decides to climb a mountain that is 4000 m high.
a) How much potential energy is gained by the climber by climbing to the top of the
mountain?
b) If the body’s efficiency in converting energy stored as fat to mechanical energy
is 25%, determine the amount of amount of energy stored that the climber will use
up in providing the energy required to raise the climber up the mountain.
c) It is estimated that one kilogram of body fat will provide 3.8 x 107 J of energy.
What amount of fat will the climber burn while climbing the mountain?
Chapter 6: Wave Motion 99
Chapter 6: Waves Motion
6.1 Wave Properties
mechanical waves require a ____________(water, air, springs)
_______________ waves require no medium (light, radio, micro)
Types of Mechanical Waves
Transverse
particles of the medium vibrate ______________ to the direction
of the wave.
eg. guitar strings
Longitudinal
particles of the medium vibrate _________ to the direction of the
wave.
eg. sound waves
Wave Pulse
a __________ disturbance that travels
through a medium.
Periodic Wave
a series of pulses at ___________
intervals (____________ wave).
Chapter 6: Wave Motion 100
Describing Waves
Period (T) - the time needed for ______ complete cycle or wave.
Frequency (Hz) - the __________ of complete cycles per __________.
ƒ = 1 T = 1_
T ƒ
Ex#1: A swing rocks back and forth 15 times in one minute.
a)What is the frequency of the swing?
b)What is the period of vibration of the swing?
Ex#2: A pendulum takes 5 s to complete one swing.
a) What is the frequency of the pendulum?
b) How many times will the pendulum swing in one hour?
Chapter 6: Wave Motion 101
Wave Velocity
the product of the __________ and the ________________.
We know: v = d or v = λ
t T
But if T = 1/ƒ
Then by substitution: v = ƒ λ
v = ______________ of the wave (m/s)
ƒ = ______________ (Hz)
λ = ______________ (m)
Ex#1: The wavelength of a water wave is 0.55 m. If the frequency of the
wave is 4.0 Hz, what is the speed of the wave?
Ex#2: A hiker on Mount Baker shouts across a valley to the other hillside,
750 m away. The echo is heard 4.4 s later.
a) What is the speed of sound in air.
b) If the sound’s frequency is 436 Hz, what is the wavelength?
Ex#3. Mac and Josh stand 8 m apart and demonstrate the motion of a
transverse wave on a snakey. The wave has a vertical distance of 32 cm from
a trough to a crest, a frequency of 2.4 Hz, and a horizontal distance of 48 cm
from a crest to the nearest trough. Determine the amplitude, wavelength and
speed of such a wave.
Chapter 6: Wave Motion 102
Wave Velocity
Wave __________ is dependent upon the medium.
eg. spring tension, water depth
If speed decreases, wavelength ________ (frequency remains
constant).
Frequency can only be changed at the __________.
If frequency increases, wavelength will ________ to maintain the same
speed..
Amplitude of a Wave
the amplitude of a wave is its ____________ displacement from the
rest position.
in order to produce a wave with ________ amplitude, more work has to
be done.
Chapter 6: Wave Motion 103
Wave Equation Name: ______________ Block: ___
1. Radio Station WBOS in Boston broadcasts at a frequency of 29.9 MHz. What is the
wavelength of the radio waves emitted by WBOS? MHz= Megahertz= 1 million Hertz or 1.00x106Hz The velocity of a electromagnetic waves is 3.00x108m/s
2. In California, Clay is surfing on a wave that propels him toward the beach with a speed
of 5.0 m/s. The wave crests are each 20m apart. A) What is the frequency of the water
wave? B) What is the Period?
3. Harriet is told by her doctor that her heart rate is 70.0 beats per minute. If Harriet’s
average of blood flow in the aorta during the systole is 1.5x10-2 m/s, what is the
wavelength of the waves of blood in Harriet’s aorta, created by her beating heart?
4. Dogs are able to hear much higher frequencies than humans are capable of detecting.
For this reason, dog whistles that are inaudible to the human ear can be heard easily by
a dog. If a dog whistle has a frequency of 3.0 x 104 Hz, what is the wavelength of the
sound emitted? Speed of sound waves in air is 340m/s
5. While flying to Tucson, Connie’s’ plane experiences turbulence that causes the
coffee in her cup to oscillate back and forth 4 times each second. If the waves of
coffee have a wavelength of 0.1m, what is the speed of a wave moving through the
coffee?
Chapter 6: Wave Motion 104
6. At a country music festival in New Hampshire, the Oak Ridge Boys are playing at the
end of a crowded 184-m field when Ronny Fairchild hits a note on the keyboard that has
a frequency of 440 Hz. A) How many full wavelengths are there between the stage and
the last row of the crowd? B) How much delay is there between the time a note is
played and the time it is heard in the last row? Speed of sound waves in air about 340.0 m/s
7. Radio Station KSON in San Diego broadcasts at both 1240 kHz (AM) and 97.3 MHz
(FM). A) Which of these signals, AM or FM, has the longer wavelength? B) How long is
each? Remember, radio waves are what kind of waves?
8. What is the wavelength of a B note (frequency 494 Hz) played by a flute?
9. Find the wavelength of the ultrasonic wave emitted by a bat if it has a frequency of
4.0x104 Hz. (This is a sound wave.)
10. As an anchor is being hoisted out of the water, it hits the hull of the ship, causing the
anchor to vibrate with a frequency of 150Hz. If the speed of the sound in sea water is
1520 m/s, how many wavelengths of sound will fit between the boat and the ocean
bottom 395 m below?
11. A popular pastime at sporting events is “the wave”, a phenomenon where individuals in
the crowd stand up and sit down in sequence, causing a giant ripple of people. If a
continuous “wave” passes through a stadium of people with a speed of 20 m/s and a
frequency of 0.5Hz, what is the distance from “crest” to “crest” (in other words, the
wavelength of the wave)?
Chapter 6: Wave Motion 105
6.2 Wave Phenomena
Wave Interference
The speed of a mechanical wave depends upon the __________
e.g. depth of water, temperature or the air, spring tension
When a wave hits a boundary or moves from one medium to another, it will be
__________, __________, and/or __________.
Reflected wave: bounces ________ in the direction it came from
Refracted wave: continues forward but changes ________ and
________ as it enters the new medium
Absorbed wave: wave energy is converted to other forms such as
________ and ________
Chapter 6: Wave Motion 106
Reflection of Waves
Law of Reflection - angle of _________ is equal to the angle of
__________.
reflected wave decreases in ___________ (waves lose energy due to
friction and absorption by barrier).
Refraction
waves change __________, __________, and ___________ at the
boundary between 2 different media (ie. different depths of water)
Chapter 6: Wave Motion 107
when waves enter shallow water:
a) frequency is the _________(only
changed at the source)
b) wavelength _________
c) speed __________
Boundary Behaviour
When a wave travels between media with different densities, it is both
reflected and transmitted (refracted).
Less Dense to More Dense: Reflected
wave is _________
More dense to less dense: Reflected
wave is _________
* TRANSMITTED WAVE IS ALWAYS ERECT
Free End
(______ dense to _____ dense):
Reflected wave is erect.
Fixed End
(______ dense to ______ dense):
Reflected wave is inverted.
Chapter 6: Wave Motion 108
Superposition of Waves
the _________ displacement of a particle caused by two or more waves.
equal to the _____ of the displacements produced by individual waves.
Constructive Interference
troughs of the 2 waves occur at the same time; combined wave is
__________ than each of the separate waves.
Destructive Interference
crests of one wave arrives at the same time as the troughs of the other
wave; net _____________ is zero.
Partially Destructive Interference
when 2 waves meet somewhere ________ the 2 extremes, or if waves
have different ____________ or different ______________.
Chapter 6: Wave Motion 109
Diffraction
the ______________ of waves around the edge of a barrier.
waves will ______ as they pass through an opening or around an
obstacle.
greater wavelength = __________ diffraction.
Doppler Shift
change in ___________ resulting from movement of wave source
i.e., change in pitch of ambulance siren as it approaches compared to
when it moves away
frequency of _______ doesn’t change, but the waves are ___________
together as the source moves towards the receiver; therefore, the
frequency of the ______________ wave is greater.
Chapter 7: Light and Geometric Optics 110
Chapter 7: Light and Optics
Electromagnetic Spectrum
• Visible light causes ________ and ________ fields to vibrate, so it is
called __________________ radiation.
• Unlike ___________ waves such as sound, electromagnetic radiation can
travel without a medium – it will transmit through the ________ of space.
• ________ light is only one type of the electromagnetic radiation;
• there are forms with wavelengths both ________ and ________ than
visible light.
Colour
Newton produced colours when a narrow beam of sunlight passed
through a ________.
__________ – arrangement of colours from red to violet
(__________).
Each colour is associated with a specific __________.
When light strikes an object, some colours may be _________ while
others are ___________
Only _________ light is seen
i.e., red cloth reflects red and absorbs other colours
7.1 Reflection
Ray Model of Light
Another model for light is that it is made up of tiny particles
called _________.
Chapter 7: Light and Geometric Optics 111
Photons travel in perfect, _______ lines ______ from a light source
We can draw pictures using straight arrows, or ________, to
represent light moving _________ from a light source. This is called
a _____________.
This model helps us to understand and predict light’s ___________,
particularly with _________ and _________.
Shadows
Ray diagrams can be used to explain _________
Light from a light source is _________ by an object, casting a
shadow _________ the object
The ________ of the shadow depends on the ___________from the
light source
Pinhole Camera
Light travels in ________ lines from various parts of an object.
Chapter 7: Light and Geometric Optics 112
Reflection
When light bounces off an object, we say it __________
The incoming ray is called the __________ ray.
The outgoing ray, that bounces off the object, is called the
__________ray
A dotted line can be drawn that is ____________ to the surface of
the object; this is called the ________.
The angle between the incident ray to the
normal is the ________ as the angle of
the reflected to the normal.
Characteristics of an Image
_______ – erect or inverted
_______ – larger, smaller, same
_______– real (formed on a screen), virtual (not formed on screen)
Chapter 7: Light and Geometric Optics 113
Images in a Mirror
image appears _______ the plane
mirror
_____, same ______, and _______
image
image is inverted _______ but not
________ (lateral inversion).
7.2 Curved Mirrors
Concave shaped mirrors cause parallel light
rays to __________.
Convex shaped mirrors cause parallel light rays
to __________.
Chapter 7: Light and Geometric Optics 114
Concave Mirrors
Ce
ntr
e
of Curvature (C): geometric __________ of “sphere”
Vertex (V): centre of a r____________________
Principal Axis (P): straight line passing between the __________and the
____________________.
Principal Focus (F): the point where a group of parallel light rays striking a
converging mirror will __________through.
Focal Length (f): distance along the PA between the __________and the
_________________
Images formed in Concave Mirrors
distant objects appear to be ________ and upside down (‘________)
As you approach the focal point of the mirror, the object gets
________, but is still ________
If an object is between the focal point and the mirror, the image is
________ and ________.
Uses for
Concave
Mirrors
Chapter 7: Light and Geometric Optics 115
lights placed at the focal point will reflect out of the mirror in
________ lines – used in ________ and ________
make-up and shaving mirrors are concave so that your image is
________ (making it easier to see)
Real vs. Virtual Images
An image is REAL if rays actually __________ and pass through the
image. A real image can be seen on a __________.
An image is VIRTUAL if rays only appear to be __________ from a
point.
Finding Images in Concave (Converging) Mirrors:
Draw at least two of the following rays:
1. A ray drawn __________ to the PA is reflected through F.
2. A ray drawn through F is refected __________ to the PA.
3. A ray that passes through C is reflected ______________ along
the same path.
Chapter 7: Light and Geometric Optics 116
CONCAVE MIRRORS
Images in
Concave
Mirrors
Object Image
Beyond C
At C
Between C and F
Between F and Mirror
Chapter 7: Light and Geometric Optics 117
Spherical Aberration
spherical mirrors are unable to focus parallel light rays to a
__________
a perfectly made mirror is slightly __________, and has no spherical
aberration.
Chapter 7: Light and Geometric Optics 118
Mirror Equation
The location in a concave mirror can be predicted using the mirror
equation:
do = distance from object to mirror
di = distance from image to mirror
f = distance from focal point to mirror (focal length)
Ex. #1:An object is placed 25 cm in front of a concave mirror with a focal
length of 15cm. Where will the image form?
Ex#2: When an object is placed 15 cm in front of a concave mirror, the
image forms 20 cm behind the mirror . What is the focal length of the
mirror?
Chapter 7: Light and Geometric Optics 119
Convex Mirrors
Focus and Centre of Curvature are both found behind the mirror.
Images in Convex Mirrors
Always _________ (diverging light rays)
_________ in size
_________
located between V and F
NOTE: Because image is ________ in size, there is an _________ FIELD
OF VIEW (useful in rearview mirrors, security mirrors, etc.)
Uses for Convex Mirrors
________ mirrors in stores
side-view mirrors in ________
Finding Images in Convex (Diverging) Mirrors
1. A ray directed to F reflects back _________ to the PA
2. A ray parallel to PA reflects back as though it has ___________ F.
3. A ray appearing to pass through C will ___________along the same
path.
Chapter 7: Light and Geometric Optics 120
Images in Convex Mirrors
Chapter 7: Light and Geometric Optics 121
7,3 Refraction of Light
Speed of Light
Galileo tried to measure the speed of light with _________ but
human reaction time limited his ability to measure time.
Ole Roemer was a Danish astronomer who studied the moons of
_______. He was the first to take data from which the speed of
light could be measured.
A.A. Michelson won the Nobel Prize for his measurement of the speed
of light with an eight-sided ___________.
Speed of light in a vacuum,,c =_____________ m/s
Chapter 7: Light and Geometric Optics 122
Refraction of Light
light travels at different ________ through different _________;
light will ______ (or change direction) as it moves from one medium to
another (at a _________ angle).
Incident ray
i fast (air) slow (glass) Refracted Ray
i
slow (glass) r fast (air)
r
emergent ray
light travelling from
a) fast to slow, bends ____________ the normal
b) slow to fast, bends ____________ the normal
optically dense – speed in one medium is ________ than another
medium.
Chapter 7: Light and Geometric Optics 123
Refraction causes optical ________ of objects under water. They
often appear to be ________ to the surface than they really are.
________ are formed by the refraction of light as it passes from
_____ dense hot air to ______ dense cool air.
On a hot day, air near the ________ surface gets very hot compared
to the air above.
Light traveling from the sky gets ________ as it passes through the
hot air, which then appears to eye to be pools of ________
5
Chapter 7: Light and Geometric Optics 124
Index of Refraction
Optical density – describes the relative _______ of light in a given medium
i.e., slow speed = __________ optical density
Index of refraction – _____________ of optical density
n = c
vm
n = index of refraction
c = speed of light in a vacuum
vm = speed of light in new medium
the greater the index of refraction, the ________ the medium
Ex#1: If the speed of light in ethanol is 2.20 x 108 m/s, what is its index
of refraction?
Ex#2: What is the speed of light in water? (n=1.333)
Chapter 7: Light and Geometric Optics 125
Speed of Light Name: ______________ Block: __
1. Use the table on your data sheet to find the speed of light in:
a) ethyl alcohol b) fused quartz c) heavy flint glass
(2.21x108 m/s; 2.08x108 m/s; 1.82x108 m/s)
2. The speed of light in a plastic is 2.00 x 108 m/s. What is the index of refraction
of the plastic?
(1.50)
3. The speed of light in a substance is measured to be 1.24 x 108 m/s. Using the
table in your data booklet, identify the substance.
(diamond)
4. Suppose you had two pulse of light ‘racing’ each other, one in air, and the other in
a vacuum. You could tell the winner if the time difference is 10 ns (10x10-9s).
How long would the race have to be to determine the winner?
(10 km)
Chapter 7: Light and Geometric Optics 126
Snell’s Law
Dutch scientist: Willebrord Snell
“ A ray of light bends in such a way that the ______ of the sine of the
angle of incidence to the sine of the angle of refraction is a __________.”
n = sin i
sin r
n = index of refraction
i = angle of incidence
r = angle of refraction
Note: this formula only applies to a ray travelling in a ________ into
another medium.
General Equation
ni sin i = nr sin r
ni = index of refraction of incident medium
sin i = angle of incidence
nr = index of refraction of second medium
sin r = angle of refraction
Ex#1: A ray of light traveling through air (n = 1.00) is incident upon a
sheet of flint glass (n = 1.61) at an angle of 45.0o. What is the angle of
refraction?
Chapter 7: Light and Geometric Optics 127
Ex#2. A ray of light traveling through air (n = 1.00) is incident upon an
unknown liquid at an angle of 33.0o. If the angle of refraction is 21.7o, what
is the index of refraction for the unknown liquid?
Snell’s Law Practice
1. If you double the angle of incidence, the angle of reflection also doubles. Does
the angle of refraction?
2. You notice that when a light ray enters a certain liquid from water, it is bent
towards the normal, but when it enters the same liquid from crown glass, it bends
away from the normal. What can you conclude about its index of refraction?
3. Light in air is incident upon a piece of crown glass at an angle of 45.0o (n=1.52).
What is the angle of refraction?
(27.7o)
4. A ray of light is incident upon a diamond (n=2.42) at 45.0o. What is the angle of
refraction? Compare your answer to Problem 3. Does glass or diamond bend light
more?
(17.0o, diamond bends more)
Chapter 7: Light and Geometric Optics 128
5. A ray of light has an angle of incidence of 30.0o upon a block of quartz and an
angle of refraction of 20.0o. What is the index of refraction for this block of
quartz?
(1.46)
6. A light ray strikes the surface of a pond at an angle of incidence of 36.0o. At
what angle is the ray refracted?
(26.2o)
7. A ray of light passes from water into crown glass at an angle of 23.2o. Find the
angle of refraction.
(20.2o)
8. Light goes from heavy flint glass into ethyl alcohol. The angle of refraction in the
ethyl alcohol is 25o. What is the angle of incidence in the glass?
Chapter 7: Light and Geometric Optics 129
Total Internal Reflection and Critical Angle
partial ________ and partial ________ occurs when light travels to a
less dense medium.
As the angle of incident increases:
Refracted ray becomes ______ intense;
Reflected ray becomes _______ intense;
Angle of refraction _________;
Maximum angle of refraction is ____. Beyond this point, all the
incident light is ________ internally.
Critical angle – the angle at which the incident ray forms an angle
of refraction at ____.
Ex#1: What is the critical angle for light passing from crown glass (n=1.52)
into water (n=1.33)?
Ex#2: The critical angle for light passing through a medium incident with
air is 24.4 o. Calculate the index of refraction for the medium. What is the
medium?
Chapter 7: Light and Geometric Optics 130
Critical Angle
1. If you were to use quartz and crown glass to make an optical fibre, which would
you use for the coating layer? Why?
(quartz)
2. Is there a critical angle for light going from glass to water? How about water to
glass?
(only glass to water)
3. Which two pairs of media, air and water or air and glass, have the smaller critical
angle?
(air and glass)
4. Find the critical angle for diamond.
(24.4o)
5. A block of glass in air has a critical angle of 45.0o. What is its index of
refraction?
(1.41)
6. A ray of light in a tank of water has an angle of incidence of 55o. What is the
angle of refraction in air? Explain.
(total internal reflection)
7. The critical angle for special glass in air is 41o. What is the critical angle if the
glass is immersed in water?
(61o)
Chapter 7: Light and Geometric Optics 131
7.4 Optics (Lenses)
Light bends as it passes from air into a glass (or another transparent)
object.
Depending on the object’s shape, light rays can be manipulated to
converge or diverge as they pass through it.
Converging or Convex Lens Diverging or Concave Lens
Optical Centre (O): geometric _________ of the lens
Focal Point (F): parallel rays _________ at focal point.
Principal Axis (PA): perpendicular to _________ of lens.
Focal Length (f): distance between___ and ___, measured along the PA.
Converging Lenses
Converging lenses have 2 ___________, located at the same focal
length on ______________ of the lens.
There is some lateral _________ that occurs when rays pass through
the lens; however, it is insignificant in thin lenses and therefore
ignored in our diagrams
Chapter 7: Light and Geometric Optics 132
Images Formed by Converging Lenses
1. A ray that is parallel to the PA is _________ through F.
2. A ray that passes through F is refracted _________ to the PA.
3. A ray that passes through O goes ______________, without
bending.
Object Image
Beyond C
At C
Between C and F
Between F and O
At F
Uses for Convex Lenses:
___________ glass
Overhead ___________
__________
___________ (long-sighted)
Chapter 7: Light and Geometric Optics 133
Chapter 7: Light and Geometric Optics 134
Diverging Lenses
Parallel rays are ________ so that they radiate out from a virtual
focus.
Image is always _________, _________, _________, and located
between ___ and ___.
Images formed by Diverging Lenses
1. A ray that is parallel to the PA _________ as if it originated from
the F on the object’s side of the lens.
2. A ray that is drawn as if it would pass through the opposite F will
refract parallel to the _________
3. A ray that passes through O goes ____________the lens without
bending.
Chapter 7: Light and Geometric Optics 135
Chapter 7: Light and Geometric Optics 136
Uses for Concave Lenses
some ________ (near-sightedness)
some ________
____________ in doors
Correcting Vision Problems
Near-sighted vision
Can not clearly focus on
_______________ objects
Occurs because the lens
___________________ the light
rays to form an image
__________________ of the retina
A ____________ lens is used to correct ________________ vision
Far-sighted vision
Can not clearly focus on
_______________ objects
Occurs because the lens
_____________ the light rays to form
an image ______________ the retina
A ___________ lens is used to correct
______________ vision
Astigmatism
______ vision due to an irregularly shaped
________
causes the image to ______ on more than
one point on the ___________
Chapter 7: Light and Geometric Optics 137
REVIEW SHEET: LENSES Name: ______________
Date: ____________
1. Label the parts on the following diagrams:
A ___________________ A ____________________
B ___________________ B ____________________
C ___________________ C ____________________
D ___________________ D ____________________
2. Find and describe the images for the following objects:
Attitude:
Size:
Type:
Attitude:
Size:
Type:
3. Two converging lenses of the same shape are constructed, one from
diamond (n=2.42) and one from glass (n=1.50). Which lens has the
smaller focal length? Explain your answer.
Chapter 7: Light and Geometric Optics 138
4. A converging lens in a photocopy machine makes images the same size
as the object. If the items to be copied are placed at a fixed
distance of 30 cm from the lens, what is the focal length of the lens?
5. A lens can be formed by a bubble of air in water. Is such a lens a
converging one or a diverging one? Use a diagram in your answer.
6. Find the principal focus in the following diagrams:
Chapter 7: Light and Geometric Optics 139
Polarization of Light
Ordinary light contains electromagnetic waves vibrating in ____
direction perpendicular to its direction of travel.
On average, _____ the waves travel in one plane and the other half
travel in the plane _____________ to the first.
A polarizer will permit only light of ______ plane to be transmitted.
Chapter 8: Special Relativity
Chapter 8: Special Theory of Relativity
Albert Einstein in 1905 described:
a) how _______is affected by motion in _______ at a constant velocity.
b) How _______ and _______are related.
Postulates of Relativity
1. All laws of _______are the same in all _________moving frames
of reference.
The laws of physics within a ______________ laboratory are the
same as those in a _________laboratory (i.e., an airplane traveling
at a constant speed).
No experiment can be devised to detect the state of
_______motion (acceleration, however, is easy to detect!).
Motion is relative.
Motion requires a______________, or the position from which
motion is observed.
One frame of reference is as valid as any other frame of reference
that moves _______ with respect to the first.
2. The ______________ in empty space will always have the same
value, regardless of the _______ of the _______ or the motion of
the observer.
Every measurement of the speed of light in empty space is
_____________, regardless of the speed of the source or the
observer.
The _________of the speed of light unifies______________.
Chapter 8: Special Relativity
Speed is USUALLY a relative quantity.
A baseball thrown at ___ km/h from a stationary truck approaches you
at ___ km/h.
A baseball thrown at ___ km/h from a truck moving away from you at 40
km/h has a speed of ___ km/h relative to you.
Relativity turns around some of our common conceptions!
Our Conceptions Tell Us… Relativity Tells Us...
Time is _______ __(absolute) Time is _________
Speed is _________to the
source or observer
Speed of light is _______
(absolute!) regardless of the
source or observer
Motion in space affects motion in time.
Time _______ (stretches) when we move through space, altering our
rate of moving into the future.
Time dilation is very _______ at everyday speeds, but __________as
you approach the speed of light.
Space and time are two parts of one whole (CALLED SPACE-TIME!)
When standing still, all your travel is through_______.
When you move, some of your travel is through space, and most is
through_______.
As you approach the speed of light, however, _______of your travel is
through space, rather than time.
If you were able to travel at the speed of light, ____of your travel
would be through space, and ______ of it through time…at c, time
stands still!
Chapter 8: Special Relativity
The Light Clock
Consider a “light clock”, where a light _________between parallel
mirrors at _______intervals of time.
An observer moving with a light clock in a space
ship observes the light flash moving _______
between the mirrors of the light clock.
An observer who is passed by the moving spaceship observes the flash
as moving along a _________ path.
In both cases, the _____________ must be the same; however, from
the frame of reference outside the spaceship, the light has traveled a
longer_______;
If the speed of the light can’t change, then the ______it takes for the
light to travel must change! Therefore, the clock ticks _______from
the perspective outside the spaceship.
From the perspective on the spaceship,
however, time has not slowed at all!
However, the occupant of the ship would
view the observer on earth as having a
_______clock and all events to be slowed
(or dilated).
From the perspective of the spaceship, the observer is _________
from his frame of reference, and therefore he views the _________
effects on the observer on earth.
Chapter 8: Special Relativity
Twin Paradox
An astronaut who is an identical twin, takes a high-speed round-trip journey while his twin brother remains on earth. When the traveling twin returns, he is younger than his stay-at-home brother!
Imagine that the rocket leaves earth and sends out light signals to earth
at 6 minute intervals.
Because of time dilation, the observer sees those light signals as being
sent out at ___ minute intervals.
On the return trip, the rocket continues to send out signals every 6
minutes, but the observer on earth would see those light signals as being
sent out at ___ minute intervals.
If the rocket travels away for one hour and back for one hour…
On the Space Ship… On Earth…
Trip away...
10 flashes x 6 min/flash = ___ minutes
have passed
Trip away…
10 flashes x 12 min/flash = ___ minutes
have passed
Trip back…
10 flashes x 6 min/flash = ___ minutes
have passed
Trip back…
10 flashes x 3 min/flash = ___ minutes
have passed
Total time for trip = ___ min Total time for trip = ___ min
Chapter 8: Special Relativity
Space and Time Travel
Before the special theory of relativity, it was believed that space travel
to the stars would take _______than a lifetime.
Since time on a high speed space craft would be_______, astronauts
traveling at 0.99c could go to the star Procyon (11.4 light years away) in
a round trip of _____ earth years;
Because of time dilation, only ___ years would go by for the astronauts!
Therefore, astronauts could travel great _______ within their
lifetimes; however, they would come back to a much _______ planet!
Time travels only _______…it is only possible to travel to the_______; you would not be able to return to the_______!
Time Dilation
When an object (such as a space ship) is travelling near the speed of
light, the time interval between two events that occur at the same place
on the moving object seems longer from the perspective of a stationary
observer than it does from the perspective of the moving observer.
In other words, time appears to be dilated, or stretched out. The
stationary observer thinks that the traveler’s clock has slowed down.
Therefore, when a spaceship is travelling close to the speed of light, its
inhabitants will age more slowly from the perspective of an Earth-based
observer
Chapter 8: Special Relativity
This dilation is written as:
Where,
∆to = time interval between two events, as measured by an observer who is
in motion with respect to the events
∆t = time interval between two events, as measured by an observer who is
at rest with respect to the events (also called the proper time);
v = speed of the moving object
c = speed of light (3.00 x 108 m/s)
Example: A light beam takes 3.0 x 10-8 s to bounce back and forth vertically
between two mirrors inside a moving spaceship, according to an observer on
board the spaceship. How long would the beam take according to an observer
on Earth, if the spaceship were moving directly overhead in a direction
perpendicular to the line of sight, with a speed of 0.60 c.
Chapter 8: Special Relativity
Length Contraction
Einstein predicted that objects moving at speeds greater than zero will
measure shorter than when they are at rest.
This shortening only occurs in the dimension of motion:
l lo 1v2
c2
l = length of object measured by an observer in motion with the
object
lo = length of object measured by an observer at rest relative to
object in motion
Ex#1. How long would a 3.00 m long space ship appear to be if it moves past
you with a speed of 0.900c?
Ex#2: If the above space ship appears to be 0.400 m long, how fast is it
traveling relative to the speed of light?
Chapter 8: Special Relativity
Mass-Energy Equivalence
Einstein was able to show mathematically that mass and energy (like
space and time!) are different aspects of the same thing..
The mathematical relationship is:
Emc2
1v2
c2
When a body is at rest, v = 0 and the total energy equation reduces to:
E = mc2
Einstein predicted that mass could be converted into energy, and that
energy could be converted into mass.
This was proven experimentally with nuclear fission reactions (i.e.,
nuclear reactors and atomic bombs).
This mass-to-energy conversion releases enormous amounts of energy
Ex#1: How much energy would be released if 1 kg of mass is converted to
energy?
148
FORMAL LAB REPORTS TITLE OF EXPERIMENT Full Name
Date of Experiment
Block/Teacher
PROBLEM
The problem or purpose states exactly what we are trying to do or find out in the
experiment.
HYPOTHESIS
An explanation of what we think will occur based on reasoning or observation; usually
written as an If…then… statement.
PROCEDURE
Steps used to test your hypothesis or theory; a description of what we must do. Follow
instructions in textbook or as instructed by your teacher. It is permissible to refer to an
attached labsheet or text pages if there are no changes made.
DATA
This section is a record of all information collected during the procedures. Any set of
measurements should be arranged in a table/graphs with headings. Where measurements
are recorded, units must be stated. Provide drawings (in pencil unless computer-designed)
where necessary and label all parts. Sketches should be simple line drawings. Describe all
observations in point form.
DISCUSSION QUESTIONS
Number each question and answer in complete sentences. Underline any important words
or phrases.
CONCLUSION
Answer questions stated in the problem. Summarize your discoveries and discuss your
results further. Explain sources of experimental error.
GENERAL POINTS
Write up lab in pen, drawings in pencil. Alternately, your lab may be typed and
printed.
Underline in contrasting colour (preferably red if in pen, or bolded if typed).
Use a ruler for drawing tables, charts, underlining and drawing arrows.