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Course Review

Read your Project Reports


Review the Studio and Lecture Quizzes


What did you do, how did you do any calculations,
what units were involved and what were the
conclusions
Make sure you know how the answer was obtained.
If it was conceptual be sure you understand the
concept
Reread the article references
 See the syllabus for the instruction given in the
studio. This is important
New Technology
 Who

developed major technology
Roughly when
 What
is the application of this technology
WEEK 1 – Conservation of Energy
 Project
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
on Solar Cells
Different forms of energy
Joules and watts
 Hypothesis,
efficiency, averages, graphs
 Lecture
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
Cost of electricity
Energy conservation
Entropy
Every time forces triggered by the
stored energy make things move, we
say that those forces do work.
Energy is therefore the capacity
for doing work in its broadest
sense.
Motion, heat, electricity, magnetism,
light, can be made to do work, thus,
they all embody different forms of
energy
What is kWh ?
An appliance rated at 1 kilowatt
(1 kilowatt = 1,000 watts)
consumes one kilo-joule of energy
(same as 1,000 joules) in every second.
1 kilowatt = 1 kilo-joule / 1 second
1 kW = 1 kJ / s
By the same token, the energy used by a
one-kilowatt appliance in one hour
(called 1 kilowatt-hour), that is,
1 kilo-joule / second x 3,600 seconds,
is 3,600 kilo-joules
Thus:
1 kilowatt-hour = 1 kilo-joule/second x 3,600 seconds
= 3,600 kilo-joules
1kWh = 1kW x 1h = 3,600 kJ
Law of conservation of
energy
The conversions of energy are never fully
effective because some of the energy
becomes low grade (unusable) heat
However
Initial energy = useful energy resulted
+ energy wasted
The total energy is conserved!
The Law of Entropy
*The natural
processes lead
to
increase in
disorder
*Natural
processes are
irreversible.
WEEK 2 – Direct comparison with a standard
 Project
on Measurement, area, volume
mass and density

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How to convert between units
suffixes to denote very large or very small
numbers
significant figures
 No
lecture
TIME, MASS and LENGTH

Time
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
Mass
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
Fundamental unit is the second (USA and SI)
Now measured by frequency of light
Fundamental unit is the kg (SI) or pound(USA)
Still a chunk of metal
Length
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Fundamental unit is m (SI) or yard (USA)
Now measured by distance light travels
WEEK 3 – MEASUREMENT WHEN NO
DIRECT COMPARISON IS POSSIBLE
Measurements when you can’t do
a direct comparison with a standard
 Project
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Using ratios to measure height or length
Measuring many items when one is too small
Scientific notation
 Demonstration
on finding the size of a
molecule
 Lecture – calibration standards
Indirect Measurement
Rule height
Ruler distance
=
Object height
Object distance
SCIENTIFIC NOTATION
 LARGE
NUMBERS
2 significant figures
390,000,000,000,000,000,000,000
can be written as

and small numbers
3.9 x 1023
3 significant figures
0.000000960 can be written as
9.60 x 10 -7
WEEK 4 – HEAT TRANSFER
 Project

– cooling a cup of liquid
Effect of cup material and starting temperature
 Temperature
scales, ways of losing heat
 Lecture
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Materials of the ages, gold, bronze, iron
Wood, glass, metals
Ceramics, plastics, composites, superconductors
All Things Known to a PHY107
Student

Gold
 Bronze
 Iron and Steel
 Ceramics
 Plastics
 Composites
 Aerogels
 Superconductors
WEEK 5 – CHOOSING MATERIALS
 Project
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Effect of load, length and thickness
 Lecture
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– properties of elastic cords
4
Internal structure
crystals
Stress, strain, elastic constant
Deformation
•STRESS = force applied per unit area
•STRAIN = change in length
original length
•ELASTIC MODULUS = STRESS/STRAIN
The stiffer the material, the less the
length will change under same stress
Graph of stress versus strain
WEEK 6 – REFLECTION and REFRACTION
 Project
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–properties of light
Names and locations of angles
Refractive index and Snell’s law
Total internal reflection
 Speed
of light changes with material
 Lecture 5


Properties of light, reflection, refraction,
scattering
Human vision and correcting defects
VISIBLE LIGHT
 Small
part of the electromagnetic
spectrum
 Travels in straight line in same medium
 Can be reflected, refracted, scattered and
absorbed
 Nothing can move faster than light in a
vacuum
 Possesses energy
We may think that radio waves are completely different
physical objects or events than gamma-rays. They are
produced in very different ways, and we detect them in
different ways. But are they really different things? The
answer is 'no'. Radio waves, visible light, X-rays, and all the
other parts of the electromagnetic spectrum are
fundamentally the same thing. They are all electromagnetic
radiation.
WEEK 7 – USING LIGHT
 Project
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– images and objects with lenses
Magnification, distances and sizes
Image properties
Plane mirrors
Focused image with a lens
Image Formed by the Eye
WEEK 8 – COLOR and WAVELENGTH
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Project – colors, light sources and filters
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Analysis of light, wavelengths, energy
Color addition and color subtraction
Use of spectrometer
Properties of laser light
Passing light through a prism
Lecture 7
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Color by addition, subtraction and mixing
Atoms as sources of light
Wave and particle description of light
Electrical circuits, series and parallel, batteries
Color Addition
Light Sources
Color Subtraction
Paints and Filters
Light from atoms
•Light is made up of little
“packets of energy” called photons
•When you have many photons they
behave as if they were a wave
•The photons are emitted by atoms
WEEK 9 – ELECTRICAL
BATTERIES and CIRCUITS
 Project
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– making and using batteries
Effect of different battery components
Parallel and series connections
Measuring voltage and current
 Demonstrations
 Lecture

on electrostatic charge
8
Setting up circuits
How a battery works
Cathode(-)
Anode(+)
Electrolyte
Positive
ions
Insulating layer
forms on anode
CURRENT FLOW
 Current
is the flow of electrons
 By convention we say positive current
flows from the anode (+) to the cathode(-)
 At the microscopic level electrons
(negatively charged) move from the
cathode(-) to the anode(+)
How to Measure Current and
Voltage
Connectingwires
Ammeter
Copper
electrode
Zinc
electrode
A
Resistor
Voltmeter
WEEK 10 – ELECTRICITY and
MAGNETISM
 Project

– electromagnet
Effect of voltage, # of turns
 Demonstration
of motors, generators and
the relation between electricity and
magnetism
 Lecture 9 on different forms of
electromagnetic radiation


Radio, radar, heat (IR), visible, UV, X-rays
applications
WEEK 11 – ELECTRICAL CIRCUITS
 Project
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Ohms law
Resistance, voltage and current
 Lecture
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10
Development and use of computers, ENIAC
Audion, transistor and integrated circuits
Binary communications
First
Transistor
(1947, John Bardeen,
William Shockley,
Walter Brattain at
Bell Labs)
Binary Uses in Computer
Digital characters – ASCII code
Stored as a byte (8 binary digits)
Example: A = 01000001
 Arithmetic with digital
Example: 01 + 10 = 11 which means
1 + 2 = 3 in decimal
 Computer code
Instruction, what to do, where to do it, which piece
of data to use

WEEK 12 – MOTION and TRANSPORT
 Project
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Constant speed and acceleration
Potential energy and kinetic energy
Gravity
 Lecture
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11
History of automobiles and planes
Car engine cycle
Mechanics of flight and propulsion
DEFINITIONS FOR USE WITH MOTION
SPEED is how rapidly an object moves or changes its position.
It is calculated by dividing how far an object moves by the time taken to move.
Speed = (distance moved) / (time taken moving)
Example. If a runner covers 400m in 50 s, the average speed is 400m / 50 s = 8 m/s
ACCELERATION is how rapidly an object changes its SPEED (or VELOCITY)
It is calculated by dividing the change in speed by the time taken to make that change.
Acceleration = (change in speed) / (time taken to make that change)
Example. A car accelerates from rest (speed=0 m/ s) to 28m/s in 7 s
acceleration = (28 – 0) m/s / 7 s = 4 m/s per second = 4 m/s2
FORCE is what causes something to accelerate. If some object changes its speed it
has accelerated and must have had a FORCE acting on it. The larger the mass of an object
the smaller its acceleration for the same FORCE.
NEWTONS Law states that force is the product of mass and acceleration.
Force = mass x acceleration
Example. A mass of 2 Kg changes its speed from 5 m/s to 25 m/s in 2 s.
Acceleration = (25-5)m/s / 2s = 20m/s / 2s = 10 m/s per s or 10 m/s2
Force = 2 kg x 10 m/s2 = 20 Newtons
GRAVITY is the FORCE by which an object is attracted to the center of the
Earth
It is calculated by multiplying the mass by the gravitational constant(10 m/s2).
Force (Newtons) = mass (in Kg) x 10
[More precisely the Gravitational constant is 9.81 m/s2 , rather than 10 m/ s2]
POTENTIAL ENERGY(PE) is energy possessed because of height. PE can
also occur by storing energy in springs, electric fields and magnetic fields.
PE(in Joules) = mass(in Kg) x gravitational constant x change in
height(in m)
Example. Gain in PE by lifting 5 Kg up 2 meters is 5 x 10 x 2 Joules = 100
Joules
KINETIC ENERGY (KE) is energy possessed because of the movement of an
object.
KE(Joules) = ½ x mass(in Kg) x (speed)2 when speed is in m/s
Example. A mass of 5 Kg with a speed of 4 m/s has a KE = ½ x 5 x 4 x 4 = 40
Joules
MECHANICAL ENERGY is energy associated with motion and position. It is
calculated by adding together the kinetic energy and the potential energy.
In the beginning-


Charles Duryea – 1895
Ransom Olds – 1901
Henry Ford – 1903

1908 the Model T
•
$360 vs $5000
• 15 million by 1927
The Secrets of Flight

Birds
 Kites and Gliders
Balloons and dirigibles
 Propeller Driven Planes, Wright bros.
 Jet Driven Planes
 Helicopters
How a Balloon Works
WEEK 13 – ROCKETS and FLOTATION
 Project
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Archimedes principal
Reduction in weight when submerged
 Lecture
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– Flotation
12
Rockets and rocket propulsion
Balloons and dirigibles
Buoyancy-Archimede’s principle
A submerged object is pushed up with a force
equal to the weight of the water displaced
Newton’s Third Law of Motion
Newton’s Third Law of Motion:
For every action there is an equal
and opposite reaction
Rocket
Mechanisms