Review Sheet for Exam 3 PHY 101

Remember: Exam 3 will cover ALL of the material since Exam 2. This outline should help you to prepare for the exam. As usual, questions about demonstrations are quite likely -- in addition to the topics here. Barney

What does it mean to say that a motion is PERIODIC?
How is the PERIOD defined? the Frequency?
The general nature of a wave is that it carries _____ but not ______.
Waves which are not periodic are called _______.
A TRANSVERSE wave is one that ...
A LONGITUDINAL wave is one that ...
Transverse mechanical waves can only exist in __________.
Longitudinal mechanical waves can exist in ...
What happens to the speed of a pulse wave if the string is pulled with a greater tension?
Identify the terms CREST and TROUGH for a wave.
What is a WAVELENGTH?
Do pulse waves have a wavelength? Justify.
What is superposition of waves?
How is the velocity of a periodic wave related to its frequency?
What is the Dependent quantity in the equation that describes the previous question?
What are NODES? ANTINODES?
What is a Standing Wave?
What happens to a pulse wave when it reflects at a more rigid boundary?
What do we mean by INTERFERENCE between two or more waves?
What is (perfectly) CONSTRUCTIVE interference? DESTRUCTIVE interference?
In two and three dimensional problems we speak of PATH DIFFERENCE. What is it?
What are the possible path differences for constructive interference?
What are the possible path differences for destructive interference?
What is DIFFRACTION of a wave? When is it most apparent?
According to Ben Franklin, what are the two 'kinds' of charge?
What is the nature of the interaction between the two kinds of charge just mentioned?
An object receives a positive charge. Is it absolutely necessary that positive charge has been given to the object? If not give a counterexample.
What is a conductor? An Insulator? What are examples of each?
What is the idea behind "GROUNDING"?
______ is a conserved quantity. It cannot be created or destroyed - only rearranged.
When amber is rubbed with fur, the _____ becomes _____ charged and the ...
When glass is rubbed with silk, the _____ becomes _____ charged and the ...
What are the constituent particles of matter. Which has a positive charge? a negative charge? Which is neutral?
What is charging by induction? How does it differ from charging by contact?
By what process does a charged body attract uncharged bodies?
What is an electroscope?
How can you use an electroscope to determine if an object of unknown charge is positive or negative?
Who determined the mathematical form of the electrical force?
What is the mathematical form of the electrical force?
How is the electrical force similar to the law of universal gravitation?
What are major differences between the electrical force and the law of universal gravitation?
What has the smallest positive charge? The smallest negative charge?
How large are the charges mentioned in the previous question?
Which force is stronger - gravitational or electrical? Why?
Which force is dominant on the microscopic scale? Why?
Which force governs the entire universe? Why?
All contact forces except for ______ are ____________ forces. Why is this so?
In terms of force, the electric field is defined as ...
What is the direction of the electric field?
Electric field lines ________ positive charges and _________ negative charges, and ______ cross.
What is meant by a battery?
What is an electrical current? How is it defined? What is the unit of current?
What is meant by the term "a complete circuit"?
What is meant by electrical resistance? How is it defined?
Be able to state and apply Ohm's law.
What is a series circuit? a parallel circuit?
How is the electricity in your house wired - series or parallel? Be able to explain why this is so.
How is electrical power defined? What is the unit of electrical power?
What is the unit of electric potential?
What is a potential difference?
A battery has a potential difference of 9 volts between its two terminals. How much work will be done by 2 Coulombs of charge from the battery?
How is the electric field related to the electric potential difference?
STUFF ON CURRENT ELECTRICITY
Why do physicists care about blackbodies?
What does the temperature of a blackbody have to do with the radiation emitted by the blackbody?
What was the downfall of the Classical physics explanation of blackbody radiation?
What notion did Planck introduce in order to explain the nature of blackbody radiation?
According to Planck, what are the allowed frequencies in the blackbody radiation?
What is meant by a "Quanta"? A "Photon"?
What is the photoelectric Effect?
Who explained it?
For a given metal, what determines whether photo electrons will be ejected?
If an electron is to be ejected, how long does the process take?
How does the energy of the ejected electron depend on the absorbed photon?
How does the number of ejected electrons depend on the brightness (intensity) of the illuminating photons?
What property of the electron did Thomson measure?
What was Millikan able to determine about the charge on an object?
What is the smallest electrical charge that freely occurs in nature?
Describe the "Chocolate Chip Cookie" (or "plum pudding) model of the atom.
What was the downfall of the Chocolate Chip Cookie model of the atom?
What do we mean by the "Emission Spectrum" of an element?
What element was discovered in the sun before it was discovered on earth?
What are cathode rays?
What is a cathode ray tube (CRT)?
What effect did cathode rays have on a piece of photographic plate that was covered in dark cloth?
Why don't we use the cathode ray tubes shown in your text as demonstrations in class today?
What are x-rays?
What is the source of x-rays?
What is the shape of the x-ray spectrum of a metal?
Who showed that the "Chocolate Chip Cookie" (CCC) model of the atom was invalid?
What was proposed to replace the CCC model of the atom?
Be ABLE to STATE the Assumptions of the Bohr Theory for hydrogen!
What is the number "n" in the Bohr theory?
What is the smallest value that "n" is allowed to have?
Is there a largest value that "n" is allowed to have?
Are there other requirements on "n"?
How is the Radius of the electron's orbit related to "n" by the Bohr Theory?
How is the Energy of the electron's orbit related to "n" by the Bohr Theory?
What is lowest energy allowed for the hydrogen atom?
What is an eV? How many joules make 1 eV? Why is the eV used as a unit?
According to Bohr theory, how does the spectrum of Hydrogen come about?
What was de Broglie's hypothesis that required intervention by Uncle Al to save his degree?
What happened to cause de Broglie to be awarded the Nobel Prize 5 years later? (i.e. what did Davisson and Germer do?)
What did de Broglie's hypothesis have to say about the nature of the Bohr orbits? (i.e. why don't the electrons radiate when in their allowed orbits?)
Is light (or electrons) a wave or a particle or both?
What determines the kind of nature exhibited by light (or electrons)?
What is the "Wavefunction" (PSI)? Can it ever be directly observed?
How do we find the probability of finding a particle at a particular location?
If we look at a "Particle in a Box" that can't get out, what is the nature of PSI?
How does the energy of the particle in the box depend on the number of loops in the standing wave? On the integer "n"?
If we send electrons at a pair of slits what kind of pattern do we observe on the other side?
What happens if we try to find out which slit a given electron passed through?
Why does the particle in the box only need 1 quantum number? How many quantum numbers are necessary for a three-dimensional atom?
What is the Pauli Principle?
What is the Heisenberg Uncertainty Principle? Be able to state it in words and mathematically for both the momentum/position and energy/time forms.
What effect did the uncertainty principle have on the PHILOSOPHY of the time?
Why does measuring the position of a small particle like the electron very accurately affect its momentum?
Why doesn't the uncertainty principle affect our everyday lives?
The size of an atom is about how many times larger than the size of its nucleus?
What was the source of Becquerel's radioactivity?
Who discovered and named the element Polonium?
Who discovered radium? In what way was it different than polonium and uranium?
Which kind(s) of radioactive decay particles have positive charge?
Which kind(s) of radioactive decay particles have positive charge?
Which kind(s) of radioactive decay particles are neutral?
The electron has the same charge to mass ratio as which decay particle?
Which particle(s) can be stopped by a sheet of paper? By 1 m of air? By several cm of lead?
Why do alpha particles do so much damage to your cells?
What force holds a nucleus together? How does this force differ than the electrical force?
What is an isotope? Name the isotopes of hydrogen.
What is a "Transmutation" of an element?
Which type(s) of decay processes always leads to transmutations?
Which type(s) of decay processes never leads to transmutations?
What is the "Atomic Number" of a nucleus? What does it tell you that is conserved?
What is the "Mass (or nucleon) Number"? What does it tell you that is conserved?
What other quantities are conserved in nuclear transmutations?
How is the transmuted element related to the parent element for beta minus decay?
How is the transmuted element related to the parent element for beta plus decay?
How is the transmuted element related to the parent element for alpha decay?
What quantities determine whether a given nucleus will decay in the next second?
What is a half-life? What are the range of half-lives?
Are there any simple rules for predicting penetration?
What is a "RAD"? A "REM"? Why do we talk of rads for materials and rems for living tissue?
Which decay product has the largest conversion factor between rads and rems? Why?
What is the maximum recommended exposure to radiation for individuals in a year?
Where does most of this exposure come from? Be able to rank in relative order the sources: nuclear power, natural, medical, cosmic rays, etc.
What is meant by "Fission"? Are all isotopes of Uranium Fissile?
Why are "Fission Fragments" extremely radioactive?
What do we mean by chain reactions that are: Sub critical, critical and supercritical?
What are the outcomes of each? Which is desirable in a nuclear power reactor?
In what ways is a nuclear power plant similar to and different from a coal power plant?
What are the long term problems with nuclear power?
What is "Nuclear Fusion"?
When is Fusion likely to be a viable source of energy?