South Pasadena · Physics Name ______
Period ___ Date ___/___/___
Final Review South Pasadena · Physics Station 1
Unit 8-Thermal Physics
Definitions
1. What is the difference between a system’s internal energy and average kinetic energy? Describe two systems with different internal energy but the same average kinetic energy.
Internal energy – sum of all molecular energy in a system.
Average kinetic energy - temperature
2. Define temperature. = average kinetic energy of a system.
· What are two possible units for temperature and how are they related to each other?
Kelvin and Celsius are the same temperature unit but have different zero points. K=C + 273.
· What does “absolute zero” mean?
A system at 0 K, which means it has no motion.
3. Define heat. – energy transfer b/c of a difference in temperature.
· What are two possible units for heat and how are they related to each other?
Joules
Calories 1 cal = 4.184J
· In which direction does heat flow? Use and define “thermal equilibrium” in your answer.
Heat flows from hot object to cold object until they are in thermal equilibrium, or when they reach the same temperature.
4. State the Second Law of Thermodynamics in three ways.
· Heat cannot flow from cold to hot
· Heat cannot be completely converted to work
· Processes proceed in direction that maximizes entropy/disorder.
5. Give three examples of increasing entropy, and three examples of decreasing entropy.
Increase Entropy:
· S à L à G
· Increase volume
· Increase particles
Decrease Entropy:
· G à L à S
· Decrease volume
· Decrease particles
Unit 12—Vibrations/Waves & Sound Station 2
Wave Speed: Use the sample data in the table below to answer the following questions.
Wave Pattern / Distance (end to end) / Round Trip Travel Time for Pulse / Time for 10 cycles1/2 wave / 6.0 m / 2.3 sec / 6.0 s
1. What is the wave pulse speed? Speed = (6.0 m x 2)/ 2.3 sec = 5.2 m/s
2. What is the wavelength? λ = 6.0 m x 2 = 12 meters
3. What is the frequency? f = 10 cycles/6.0 s = 1.7 Hz
4. What is the wave speed? v = 12 m x 1.7 Hz = 20 m/s
Terms:Match these terms with their correct application or example.
Each name may be used once, more than once,
or not at all.
T) Transverse Wave
L) Longitudinal Wave
M) Mach #
D) Doppler Effect / T 1. X-ray.
L 2. Sound from a jet engine.
L 3. P type earthquake wave
R 4. Child swinging higher on a swing.
M 5. Jet Speed/Sound Speed
D 6. Change in pitch or frequency of a sound
T 7. S type earthquake wave
R) Resonance
Doppler Effect: (The speed of sound is 340 m/s)
If a tuning fork has a frequency of 256 Hz, and it is approaching you at a speed of 12 m/s, then:
1) will the pitch of the sound appear to you to be higher or lower? a) higher b) lower
2) Compare the speed of the sound leaving the tuning fork to the speed from a stationary tuning fork. It
will be a) higher b) lower c) the same
3) What will be the new frequency? 265 Hz (ignore this problem)
What is the wavelength of an electromagnetic wave traveling at c = 3.0 x 108 m/s if its frequency is
3.3 x 10 14 Hz? λ = 3 x 10 8 m/s / 3.3 x 10 14 Hz = 9.1 x 10 -7 m = 910 nanometers
Which of the following would most likely represent the electromagnetic wave above?
a) infra-red b) green light c) Ultra-violet light d) X rays
because red light is 700 nm and this is longer than red light
What is the beat frequency heard between two tuning forks of frequencies 386 Hz and 390 Hz? 4 Hz
Unit 13—Light and Color Station 3
Additive Colors of Light
Circle which of the following would be the three primary colors of light:
Red / Orange / Yellow / Green / BlueIdentify the new color of light created when you mix the following pairs of colors:
Red + Green =Yellow / Red + Blue =
Magenta / Green + Blue =
Cyan
Subtractive Colors of Pigments:
Write in the three primary colors of paints or pigments:
Magenta / Yellow / CyanIdentify which two primary colors of paints make which secondary color.
Magenta + Cyan = Purple / Magenta + Yellow= Orange / Yellow + Cyan
= Green
Polarizing Filters:
If light is passing through one filter, represented by this vector, ↔, draw the vector for a second filter placed on top of the first filter if none of the light is passing through both filters. They are at 90 ° to each other
Arrange the following electromagnetic waves in order from smallest to largest frequency:
Then sketch a picture of the wavelength of one wave of each:
microwaves x- rays green light radio waves ultraviolet waves
E.M. Wave / WavelengthRadio / Longest λ
Microwaves
Green
U.V.
X-rays / Shortest λ
Unit13—Reflection/Refraction, Lenses & Diffraction Station 4
Which of the following colors would be dispersed the most when passing through a prism:
Red / Orange / Yellow / Green / Blue / VioletSketch a picture of the prism showing how
the light waves refract through the prism:
Lens Equation:
Determine the focal length of a lens which has the following values for image and object distance:
di = 48.0 cm do = 8.0 cm Focal length = 6.9 centimeters
Sketch a diagram with approximate relative distances for the screen, lens and object (e.g. candle)
See picture in class
Draw a picture of a converging lens and then show the
path of three light waves (rays) passing through the lens: See picture in class
Draw a picture of a diverging lens and then show the
path of three light waves (rays) passing through the lens: See picture in class
If a laser light beam is passing through air into a tank of water, then it hits a mirror on the bottom of the tank
and reflects off the mirror then through the water and then out to the air,
a) Relative to the normal, how does the light refract when passing into the water Towards the normal
a) How does the light beam refract when passing out of the water Away from the normal
Diffraction: mλ = dsin θ
A laser of wavelength 532 nanometers is producing a diffraction pattern on a CD whose diffraction spacing pattern is 5.5 centimeters for the first order pattern. The distance from the screen to the CD is 45 centimeters. What is the spacing "d" of the pits on the CD? (First draw a simple diagram of the set up)
d = (1) (532 x 10 -9 m) = 4.4 x 10 – 6 meters
Sin 6.97 °
Unit 9—Electrostatics Station 5
1. The electrostatic force between two charges located 4.0 meters apart is 0.10 N.
What will the force be between these charges when they are located 2.0 meters apart?
a) 0.40 N b) 0.20 N c) 0.10 N d) 0.05 N
2. A 3-C charge and a 5-C charge attract each other with 20 N of force. How much force will a 3-C charge and a 10-C charge exert on each other when placed the same distance apart?
a) 40 N b) 20 N c) 10 N d) 8N
3. What is an example of a material that is a conductor? anything metal e.g. a metal screwdriver
4. What is an example of a material that is an insulator? glass, plastic, rubber, paper, wood
5. A 15-C charge and a negative 10-C charge attract each other. They are 0.20 meters apart. What is the force of attraction between them? (k = 9.0 x 10 9 N m2/C2)
F = 9.0 x 10 9 N m2/C2 x (15-C) x (10-C) = 3.4 x 10 13 Newtons
(0.20 meters)2
Unit 10—Electric Current and Electric Circuits Station 6
1. What is the voltage across a 5.0 Ω resistor is the current through it is 5.0 A?
a) 100 V b) 25 V c) 4.0 V d) 1.0 V
2. What is 1.0 Ω equivalent to? a) 1 J/s b) 1 W/s c) 1 V.A d) 1 V/A
3. A 4000 Ω resistor is connected across 220 V. What current will flow? 220 V/4000 Ω = 0.055 amps
4. Consider two copper wires. "A" has twice the length and twice the cross-sectional area of "B". How do
the resistances of these two wires compare?
a) Both wires have the same resistance. c) B has a greater resistance.
b) A has a greater resistance d) None of the above
5. A lamp uses a 150 Watt bulb. If it is used at 120 V, what is its resistance?
a) 48 Ω c) 80 Ω
b) 96 Ω d) 150 Ω
I = 150 W/120 V = 1.25 A R = 120 V/1.25 A = 96 Ω
6. A 400-W computer (computer + monitor) is turned on for 8.0 hours per day. If electricity costs 10 cents per one kilowatt-hour, how much does it cost to run the computer annually?
a) $116.80 b) $1,168.00 c) $14.60 d) $ 146.00
400 W x 1kW/1000 W x 8 hr/day x $.10/1 kW-hr x 365 d/yr = $116.80
7. A 6.0 Ω resistor and a 12 Ω resistor are connected in parallel to a 36 V battery. What power is
dissipated by the 6.0 Ω resistor? (Hint: the current through the 6.0 Ω resistor is a branch current)
a) 0.22 kW b) 48 W c) 0.49 kW d) 24 W
RT = 4 Ω
IT = 36 V/4 Ω = 9 A, so current through 6 ohm resistor is 6 amps, and
Power = IV = 6 A x 36 Volts = 216 watts or .216 kilowatts
8. A combination of 2.0 Ω in series with 4.0 Ω is connected in parallel with a 3.0 Ω resistor. What is the equivalent resistance? (Draw a circuit diagram)
a) 2.0 Ω c) 4.0 Ω
b) 3.0 Ω d) 9.0 Ω 2 ohms + 4 ohms = 6 ohms
1/6 ohm + 1/3 ohm = 1 RT so RT = 2 ohms
Final Review South Pasadena · Physics Station 7
Unit 11—Magnetism
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1. Draw the direction the compass points in each circle of the system. (4 points)
2. The direction of the current in each circuit is indicated. Show the direction of the magnetic field, using ¤ coming out of the paper and V going into the paper. (3 points)
3. A step-up transformer has 10 turns on its primary coil and 180 turns on its secondary coil. The secondary coil is supplied with 90 V of alternating current. The secondary produces a current of 55 A.
(a) What is the voltage of the primary? (4 points) I E S A
Vp = ? Vp = Vs= (90 V) = 5 V
Vs = 90 V
np = 10
ns = 180
(b) What is the current of the primary? (4 points) I E S A
Vp = 5 V Vp·Ip = Vs·Is Ip = = 990 A
Vs = 90 V
Ip = ?
Is = 55 A
(c) What is the power output by the transformer? (4 points) I E S A
Vs = 90 V P = Vs·Is = (90 V)(55 A) = 4950 W
Is = 55 A