Download ENERGY, WAVES, and ELECTRICITY UNIT REVIEW

Unit 4 Final Exam Review
Answer Vocab and Questions on a separate sheet of paper!
Terms to Know and Use:
 Potential energy
 Kinetic energy
 Waves
 Period
 Wavelength
 Amplitude
 Frequency
 Speed
 Transverse wave
What do the following units measure?
 s
 m/s2
 m/s
 m











Longitudinal
(compressional)
wave
Medium
Electromagnetic
wave
Mechanical wave
Pitch
Reflection
Refraction
Absorption









N
J
Interference
Doppler Effect
Electromagnetic
spectrum
Ampere
Voltage
Resistance
Current
Complete circuits
Open circuits
Short circuits

W
WAVES:
1. Describe a wave in terms of wavelength, amplitude, frequency and speed.
2. What are examples of transverse and longitudinal waves?
3. Compare and contrast transverse and longitudinal waves.
4. What are 3 examples of energy being transferred through waves? What is the source of vibration for each
wave?
5. Why does a fishing bobber not move forward as a wave passes underneath it?
6. Give one example that shows that sound is energy transferred by a wave, not energy transferred by
particles.
7. How does the loudness of a sound wave decrease as you move away from it? (constant, increase,
decrease, etc…). What part of the wave is related to loudness?
8. Why can we see the lightning before we hear the thunder?
9. Why does it take 8 minutes for sunlight to reach Earth?
10. Distinguish between constructive and destructive interference. Draw examples of each.
LIGHT:
1.
2.
3.
4.
5.
Describe the electromagnetic spectrum. Compare wavelength, frequency, and energy.
Why can radio waves travel through space, but sound cannot?
What is a ray diagram (think of the mirror maze lab)?
Explain refraction.
Why does the sun look yellow? Why is the sky blue? Why do sunsets and sunrises appear red and
orange?
ENERGY:
1. Explain the law of conservation of energy and give an example.
2. Why does all of the stored (potential) energy of gas not transfer into mechanical (kinetic) energy of the
vehicle?
3. Describe the transfer of potential and kinetic energy as a roller coaster goes up and down a hill. How does
the sum of the potential and kinetic energy change during this process?
4. Why do all mechanical systems require a force of some kind to maintain their motion?
ELECTRICITY:
1. How does the force between two electrons change as they move closer together (Coulomb’s Law)?
2. How does the force between an electron and a positive nucleus change if the size of the charge of the
nucleus is doubled(Coulomb’s Law)?
3. Why does acquiring excess static charge (electrons) cause you to “shock” someone if you touch them?
4. How is electricity produced in power plants (give three examples)?
5. What is the difference between voltage, resistance and current in an electric system? How do they relate to
each other and to the flow of electrons?
6. What is the difference between a series and parallel circuit in terms of what they look like and how they are
used?
7. What is a short circuit?
8. Explain the difference between a conductor of electricity and an insulator. Give examples of each.
PRACTICE PROBLEMS:
1. Name a device that transforms the first type of energy into the second:
a. Electrical into heat
b. Electrical into mechanical
c. Potential into electric
2. Identify the following as potential or kinetic energy:
a. A flag blowing in the wind
b. The rollercoaster cart at the top of the highest hill waiting to start
c. The rollercoaster cart at the bottom of the lowest valley on the coaster.
d. The energy in food
e. The energy in a stretched spring of a mouse trap
3. Draw the following circuits:
a. Open
b. Closed
c. Series with 2 bulbs
d. Parallel with 3 bulbs
Calculations Practice:
1. A wave is moving toward the shore with a velocity of 5.0 m/s. If its frequency is 2.5 hertz, what is its
wavelength?
2. A tuning fork has a frequency of 280 HZ, and the wavelength of the sound produced is 1.5 meters. Find the
speed of sound.
3. What is the potential energy of a rock with a mass of 10 kg that is sitting on top of a hill 300m high?
4. What is the kinetic energy of a ball with a mass of 0.25 kg traveling at 3 m/s?
5. A book weighing 3 N is lifted 2 m. How much work is done?
6. How much power was used to lift the book in #5 if it was done in 0.5 s?
7. A boy pushes a lever down 2 m with a force of 75 N. The box at the other end weighs 50 N and moves up
2.5 m. What is the efficiency of this lever?
8. How much current flows through a radio speaker that has a resistance of 8 Ohms when 12 V is impressed
across the speaker?
9. What power is needed to operate a clock radio if it draws a current of 0.5 A from a 120-V circuit?