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Final PH 171
Fall 2008
Name_________________________
Chapter 1:
Define (2 pts each)
1. reflection
The bending of light when strikes a surface and bounces off
2. refraction
The bending and the changing in the speed light as it passes from one optical medium
into another
3. total internal reflection
When reflection occurs in an optical medium at the interface between two medium
(3 pts each)
4. complete the following diagram showing that the angle of reflection is equal to
incidence
5. complete the following diagram
It will bend toward the normal
6. complete the following diagram
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Final PH 171
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It will bend away from the normal
7. In you every day life list 3 uses of a laser (3 pts)
(ONLY NEED THREE others are acceptable also)
Bar code scanning
Laser eye surgery
Pointer
Telecommunications
8. Why is internal reflection important in the usage of fiber optics? (4 pts)
It allows the bending of the fiber optical cable
9. How big are the strands used in fiber optics in general? (4 pts)
Smaller then a millimeter
10. List at least three properties of light (6 pts, 2pts each)
Straight line travel
186,000 miles/second
ability to reflect
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Final PH 171
Fall 2008
Chapter 2
Equations
F
P
F  ma
A
m
w

w 
V
V
P1  P2
V=Ah
wh  P
Define (2 pts each)
1. Pressure
Is a force per area
2. Archimedes Principle.
The volume of an object will be equal to the displacement of the fluid that it
submerged in.
3. Pascal’s Principle.
That the pressure in a closed container is constant on all walls of the container and
throughtout.
4. List the three states of matter and explain the properties of each state. (6pts, 2pts
each)
Solid definite volume and shape
Liquid definite volume and no definite shape
Gas no definite shape or volume
5. Solve if an object has a weight of 250 N and occupies an area of .2 cm2. What is
the pressure that the item exerts on the floor? (5pts)
F
A
250 N
P
.2cm 2
P
P  1250
N
cm 2
6. Solve if an object has a mass of 200 kg and a volume of .05 m3. What is the
density of the object? Is the object more or less dense than water? (5pts)
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Final PH 171
Fall 2008
m
V
200kg

.05m3
kg
  4000 3
m
yes

7. Explain why a dam is thicker at the bottom then at the top? (3pts)
There is a much greater pressure at the bottom of the dam than at the top, due to
the weight of the water at bottom compared to the top.
8. If an object is floating what can you say about the buoyancy force? (3pts)
That the buoyancy force on the object is equal to the weight of the object.
9. Why are fluids used in hydraulic jacks instead of gases? (3pts)
Fluids which are in the cylinders cannot be compressed
10. Solve. In a hydraulic jack, if one cylinder is 120 cm2 and the other cylinder is
1000 cm2. If the smaller cylinder has 200 lb of force exert on it. What will be the
force exerted by the larger cylinder? (5pts)
F1 F2

A1 A2
F2
200 N

2
120cm 1000cm 2
1000cm   200 N   120cm  F
1000cm   200 N   F
120cm 
2
2
2
2
2
1666.7 N  F2
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2
Final PH 171
Fall 2008
Chapter 3
Equations:
V  IR
P  VI
1. Draw an example of a series circuit.(3pts)
The one in the online material is good for this.
2. List 4 characteristics that influence the resistance of a piece of wire and how?
(8pts, 2pts each)
Length – longer the greater the resistance,
diameter (cross-sectional area) – the greater the less the resistance,
temperature – the greater the higher the resistance and
what the wire is made of – some materials are good conductors and others are not.
The next three questions will refer to the following. In a home a light bulb has rating of
150 watts and is connected into the home electrical service of 120 V. The cost of
electricity is $.07/kwh and the light is used 24 hours a day.
3. What is the resistance of the circuit? (5pts)
P  VI
150watts  (120volts ) I
I  1.25amps
V  IR
120volts  (1.25 Amps) R
R  96
4. How many kilowatt-hours does the light use in one day? One month? (5pts)
150watts  .15kilowatts
(.15kw)(24hrs )  3.6kwh
(3.6kwh)(30days )  108kwh
5. What is the cost to use the light for one month? (5pts)
(108kwh)($.07 / kwh)  $7.56
6. Discuss the three major parts of an atom. (6pts, 2 pts each)
neutron – neutral particle in the nucleus, about the same mass as the proton
proton – positive charged particle in the nucleus, about the same mass as the
neutron
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electron – negatively charged particle that surrounds the nucleus, much less
massive then the proton or neutron
7. What is a circuit breaker? Why do you need them in your home? (3pts)
A circuit breaker is a device that opens up a circuit if to much current tries to flow
through the circuit. It protects the home from the wires getting to hot and causing
a fire.
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Final PH 171
Fall 2008
Chapter 4
1. Draw a transverse wave and label with the amplitude and wavelength. (4pts)
2. Explain how a speaker produces sound waves. (3pts)
The audio signal is sent to a coil of wire, the coil of wire creates a magnetic field,
the field of the coil and the permanent magnet of the speaker are either attracted
or repelled, and the coil is connected to the cone of the speaker.
3. What is a compression of a longitudinal wave?(2pts)
It is the higher pressure regions of the wave.
4. What is frequency? (2pts)
Is the number of waves that pass a point in a given amount of time.
5. What is wavelength? (2pts)
Is the distance from one part of a wave to the next corresponding point on the
wave.
6. Explain how a microphone works. (3pts)
The diaphragm of the microphone vibrates by the sound pressure. A coil of wire
is located in a magnetic field. A current is created in the coil of wire as the
diaphragm moves.
7. Explain how your ear hears sound. (3pts)
The ear drum vibrates as the sound wave strikes it. Which causes small bones in
the ear to vibrate these vibrating bones then effect the nerves in the ear.
8. If the sound gets louder what part of the wave changes? (2pts)
The amplitude
9. If the pitch gets higher what part of the wave changes? (2pts)
frequency
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Fall 2008
10. Change the binary number 110001 to a decimal number. (4pts)
1x1+0x2+0x4+0x8+1x16+1+32=49
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Final PH 171
Fall 2008
Chapter 5
Equations
9
F  C  32
5
5
C   F  32 
9
Q  mcT
1. Explain the difference between heat and temperature. (4pts)
Heat is a form of energy. Temperature is a measurement of how hot or cold
something is.
2. If you have a temperature of 20oC
what is the temperature in Fahrenheit?
(3pts)
68oF
3. When you were making ice cream,
what occurred to the temperature of
the ice once salt was added to the
mixture? (4pts)
The temperature lowered
4. Can you have ice and water at the
same temperature? Explain. (4pts)
Yes, because both states of matter can
exist at zero degree Celsius.
5. If you have 450 grams of water and the temperature is raised from 5oC to 95oC.
How much heat was gained by the water? (5pts)
40500 calories
6. Explain how a heat pump functions. (4pts)
A liquid is evaporated forming a cold gas. The gas absorbs heat from the outside
environment. The warmer gas is compressed thus raising the temperature of the
gas. The gas loses heat to the interior of the home and becomes a liquid and the
cycle repeats.
7. What are the three ways in which heat can be transported? (6pts, 2pts each)
Convection – in a fluid
Conduction – in a solid
Radiation – by electromagnetic energy
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Final PH 171
Fall 2008
Material
Air
Rock wool
Fiberglass
Expanded polystyrene
Concrete
Cellulose (blown)
Vermiculite
Perlite
Wood 2 x4
Wallboard
Brick
Glass
Glass double pane
Glass triple pane
Window plus storm window
Asbestos cement board
Plywood
Plywood
Acoustic tile
Wood subfloor
Carpet & pad
Hardwood floor
Brick
Concrete block
Aluminum siding
Aluminum siding insulated
Wood siding
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Thickness inches
1
3
3
3
6
3
1
1
1.625
3.5
0.5
1
.125
0.75
1
2
0.25
0.5
0.75
0.5
0.75
0.75
0.75
3
8
0.375
0.375
0.375
R-value ft2 oF/(BTU/hr)
1.44
12
12
15
3.60
10.2
2.20
2.75
2.03
4.38
0.45
0.11
0.9
2
3.2
2
0.06
0.62
0.93
1.25
0.94
1.25
0.68
0.33
1.11
0.61
1.82
0.90
Final PH 171
Fall 2008
R-value of thin films
0.8
0.7
0.6
R-Value
0.5
0.4
0.3
0.2
0.1
0
0
5
10
15
20
25
30
35
Wind Speed MPH
This information will be used to answer the questions below. If a wall in a home is
composed of brick (1”), plywood (.75”), fiberglass insulation (3”) and wallboard (.5”).
Assume the wind on the outside is 5 mph and 0 mph on the inside. The wall is 40 feet
long and 8 feet high. There are 7500 heat degree days.
8. What is the Rvalue of the wall include the air movement? (5pts)
R = .11 + .93 + 12 + .45 + .68 + .31
R = 14.48
9. What is the rate of heat loss through this wall using the number of heating degree
days determined in problem 8 for the year (the units should be BTU/yr)? (5pts)
165745.8 BTU/hr/yr
165745.8 BTU/hr/yr x 24 hr = 39779000.6 BTU/yr
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Final PH 171
Fall 2008
Chapter 6
Equations for problems
Overshot mill
kg 

P   9800 2 2  Ahv
ms 

Undershot mill
kg
P  500 3 Av3
m
Define (2 pts each)
1. kinetic energy
– energy of motion
2. potential energy
– energy of gravitational position
3. work
– force through a parallel distance
4. power
– the rate of doing work
5. efficiency
– the amount of energy or power that is converted into doing the actual task
required by the devise.
6. Why does an undershot mill wheel have paddles instead of buckets? (3pts)
- the water pushes the wheel around.
7. Explain at least three design factors that you must use in the designing of an
overshot mill and how are these factors related to the power output of the mill.
(6pts, 2pts each)
The width of the water wheel the wider the wheel the more power.
The height of the water wheel the taller the greater the power output.
The flow rate of the water, the greater the flow the greater the power.
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8. Explain in detail how a mill works (it can be overshot or undershot, but you must
specify). (4pts)
Overshot mill is a potential energy device. The water falls onto the wheel, the
rate is controlled by a gate. The water strikes the wheel slightly in front the midpoint. The weight of the water causes the wheel to turn. The turning wheel
generates mechanical energy that is transferred to the inner workings of the mill.
The power of the water wheel is used to turn stones to grind grain.
9. Murray Mill located in North Carolina is an
overshot water mill. The waterwheel is 7.5
meters in height and has a width of .5 meters.
The water flows in the flume at a depth of .3
meters with a velocity of 2 meters per second.
Determine the power of the mill. (5pts)
kg 

P   9800 2 2  Ahv
ms 

kg 

 m
P   9800 2 2  .5m .3m  7.5m   2 
ms 

 s
P  22050watts
or
P  23.6hp
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Final PH 171
Fall 2008
Chapter 7
Equations
v  vo  at
1
d  vot  at 2
2
2
2
v  vo  2ad
Define (2 pts each)
1. speed
a rate of motion, the amount of distance covered in a period of time
2. velocity
a speed with a direction, a vector
quantity
3. acceleration
a change in the velocity per unit of time,
speeding up or slowing down, a vector
quantity.
4. force
a push or pull, if an unbalanced force is
present there must be an acceleration.
5. What does this graph represent? (3pts)
constant speed
6. A car starts from rest and accelerates at 1 m/s2 for 25 seconds. What is the
velocity of the car at the end of this time period? (5pts)
v  vo  at
m  m
 1   25s 
s  s2 
m
v  25
s
v0
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a
Final PH 171
Fall 2008
7. Using the car discussed in problem 6. How far did it travel while it was
accelerating? (5pts)
1
d  vot  at 2
2
2
 m
 m
d   0   25s   .5 1 2   25s 
 s
 s 
d  312.5m
8. A car traveling at 40 m/s begins to slow with a deceleration of 1.5 m/s2. It slows
until the stop light turns green. It does not come to a stop but has a slow speed of
5 m/s. How long were the brakes applied to cause this slowing? (5pts)
v  vo  at
m
m 
m
 40   1.5 2  t
s
s 
s 
t  23.3s
5
9. How far did the car travel while the brakes were applied? (5pts)
1
d  vot  at 2
2
m
2
 m

d   40   23.3s   .5  1.5 2   23.3s 
s
s 


d  524.8m
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Final PH 171
Fall 2008
Chapter 8
Equations
  mv
1
K  mv 2
2
Define (2 pts each)
1. Define Momentum
is a vector quantity and is the product of mass and velocity
2. Define Elastic Collision
both momentum and kinetic energy must be conserved
3. Define Inelastic Collision
a collision in which the objects stick together, on momentum must be conserve
4. If a 10 kg car traveling at 10 m/s strikes a stationary 5 kg car and they stick
together, what is the final velocity? (5pts)
 b   a
m1v1b  m2v2a   m1  m2 Va
10kg  10
m
  15kg Va
 s
m
Va  6.67
s
5. If the cue ball is moving horizontally and strikes the eight ball, complete the
motion of the two balls. (assume the balls do not travel in one dimension) (5pts)
One ball must go above the horizontal and one below
6. Explain conservation of momentum. (4pts)
When all the momentum before collision must equal all of the momentum after
collision
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Final PH 171
Fall 2008
Chapter 9
1. Explain the differences between a boiling water reactor and a pressurized water
reactor.
A boiling water reactor uses one closed loop and the water around the core turns
the turbines as steam and both gasses and liquids surround the core. The
pressurized water reactor uses two closed loops and the water around the core
remains in a liquid phase. A heat exchanger is used to generate steam.
2. List and discuss the three fundamental particles of which makes up atoms.
The electron orbits the nucleus and is negatively charger it is much less massive
than the other two particles.
The proton is in the nucleus and has a positive charge.
The neutron has no charge and is in the nucleus.
The neutron and proton are about the same mass.
3. Explain Fission
Fission is the process of splitting the atom by a neutron collision.
4. Explain the Three Mile Island accident.
The accident at TMI occurred due to the failure of the main feed water pump in
the secondary loop. This failure was not understood for several minutes and other
human errors occurred which caused the accident to cause a partial meltdown
from just being a typical pump failure.
Define
5. Alpha particle – a helium nuclei, made of two protons and two neutrons.
6. Beta particle – an electron from the nucleus, which occurs when a neutron decays
in to a proton.
7. Gamma ray – electromagnetic radiation which reduces the energy in an atom.
8. Who used a plum pudding model to explain the atom? - Thomson
9. Who first used discrete orbitals? - Bohr
10. Complete
50
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Sn126      51 Sb126
Final PH 171
Fall 2008
11. Complete
92
U 235    90Th 231
12. What is the half-life 40 seconds
Time (seconds)
0
10
20
30
40
50
60
70
80
90
100
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Mass (grams)
5000
4204
33536
2973
2500
2102
1768
1487
1250
1051
884
Final PH 171
Fall 2008
19-19
5/8/2017