Handed back graded Electrical Meters Lab and Circuit Exercise.
Electricity Test
Friday, May 30, 2008
Thursday, May 29, 2008
Thursday, May 29, 2008
Students finished Circuit Exercise.
Students worked on Electricity Problem Set 2.
Described briefly what is on tomorrow's test on Electricity.
Students worked on Electricity Problem Set 2.
Described briefly what is on tomorrow's test on Electricity.
Wednesday, May 28, 2008
Wednesday, May 28, 2008
Students did Circuit Exercise lab and worksheet.
Also handed out Electricity Problem Set 2 for review for Electricity Test on Friday.
Also handed out Electricity Problem Set 2 for review for Electricity Test on Friday.
Tuesday, May 27, 2008
Tuesday, May 27, 2008
Handed back Electrical Measurements Lab.
Students finished Electrical Meters Lab.
Electricity Test on Friday
Magnetism Test Wednesday, next week.
Students finished Electrical Meters Lab.
Electricity Test on Friday
Magnetism Test Wednesday, next week.
Friday, May 23, 2008
Friday, May 23, 2008
Students finished Electrical Measurement lab if they had not done so.
Introduced Electrical Meters lab. Students worked on that lab. Most students constructed the voltmeter but did not get to the ammeter section. We will finish this lab on Tuesday.
Introduced Electrical Meters lab. Students worked on that lab. Most students constructed the voltmeter but did not get to the ammeter section. We will finish this lab on Tuesday.
Thursday, May 22, 2008
Thursday, May 22, 2008
Physics Extravaganza wrap-up sheet.
Went around room asking about favorite demo.
Described how to use a multimeter. Explained resistor color codes. Students did the Electrical Measurements Lab.
Have students check with instructor before connecting power to circuits with ammeter.
Went around room asking about favorite demo.
Described how to use a multimeter. Explained resistor color codes. Students did the Electrical Measurements Lab.
Have students check with instructor before connecting power to circuits with ammeter.
Wednesday, May 21, 2008
Prepared for Physics Extravaganza.
Some students worked on their presentations. I packed equipment.
Other students painted signs.
Some students worked on their presentations. I packed equipment.
Other students painted signs.
Tuesday, May 20, 2008
Monday, May 19, 2008
Last class day before IB exam.
Handed out summary.
Went over radioactive decay - types of decay (alpha, beta, gamma)
Described the rules for writing decay equations.
Briefly describes classes of particles (leptons (light), hadrons (heavy), gauge bosons (interactions)). In equations, lepton number is conserved as is baryon number.
Hadrons consist of mesons and baryons (particles like proton and neutron)
Leptons include the electron and neutrinos.
Gauge bosons include the photon.
To conserve lepton number, in the decay of a neutron into a proton and electron, you must also have an anti-neutrino.
Went over several decay equations showing that nucleon number, charge number, baryon number and lepton numbers must be the same on both sides of the equation.
Problems in radioactive decay:
Two ways of looking at decay: delta N/delta t = - lambda * N
lamba is the decay constant = decay rate/number of remaining particles
A = Ao * (1/2)^(t/T 1/2)
T 1/2 is the half life
A is the amount remaining
Ao = original amount
The relation between the two ways of looking at decay is: lambda = ln 2/halflife
Students did several problems on radioactive decay.
**************
Went over photon energies when an electron changes energy levels. Calculated energies of photons, wavelengths, and frequencies.
Showed table of quantum numbers:
n = principal quantum number n = 1,2,3,4...
l = orbital quantum number. For a given n, l = 0, 1, 2, n-1
ml = magnetic quantum number. For a given n and l, ml = l, l-1, ...0, -1, -2, -l
ms = spin quantum number. For the electron, ms = 1/2, -1/2
Also handed out summary packets for astrophysics option.
Handed out summary.
Went over radioactive decay - types of decay (alpha, beta, gamma)
Described the rules for writing decay equations.
Briefly describes classes of particles (leptons (light), hadrons (heavy), gauge bosons (interactions)). In equations, lepton number is conserved as is baryon number.
Hadrons consist of mesons and baryons (particles like proton and neutron)
Leptons include the electron and neutrinos.
Gauge bosons include the photon.
To conserve lepton number, in the decay of a neutron into a proton and electron, you must also have an anti-neutrino.
Went over several decay equations showing that nucleon number, charge number, baryon number and lepton numbers must be the same on both sides of the equation.
Problems in radioactive decay:
Two ways of looking at decay: delta N/delta t = - lambda * N
lamba is the decay constant = decay rate/number of remaining particles
A = Ao * (1/2)^(t/T 1/2)
T 1/2 is the half life
A is the amount remaining
Ao = original amount
The relation between the two ways of looking at decay is: lambda = ln 2/halflife
Students did several problems on radioactive decay.
**************
Went over photon energies when an electron changes energy levels. Calculated energies of photons, wavelengths, and frequencies.
Showed table of quantum numbers:
n = principal quantum number n = 1,2,3,4...
l = orbital quantum number. For a given n, l = 0, 1, 2, n-1
ml = magnetic quantum number. For a given n and l, ml = l, l-1, ...0, -1, -2, -l
ms = spin quantum number. For the electron, ms = 1/2, -1/2
Also handed out summary packets for astrophysics option.
Thursday, May 15, 2008
Thursday, May 15, 2008
Went over problems from supplemental problem sheet on magnetism.
Handed out Atomic Physics packets to IB students.
Handed out Atomic Physics packets to IB students.
Wednesday, May 14, 2008
Wednesday, May 14, 2008
Went over RA 24.1
Discussed Faraday's and Lenz's Laws. Showed examples.
Demo of motor and generator.
Demo of magnet entering coil of wire.
Talked briefly about transformers.
We did problem 21 in class. Asked students to try the rest of the problems for homework.
Discussed Faraday's and Lenz's Laws. Showed examples.
Demo of motor and generator.
Demo of magnet entering coil of wire.
Talked briefly about transformers.
We did problem 21 in class. Asked students to try the rest of the problems for homework.
Tuesday, May 13, 2008
Tuesday, May 13, 2008
Went over first four problems on magnetic problem worksheet.
Gave quizzes on magnetism.
Handed out RA 24.1 due tomorrow.
Gave quizzes on magnetism.
Handed out RA 24.1 due tomorrow.
Monday, May 12, 2008
Monday, May 12, 2008
Went over RA 23.1.
Showed several examples of using the right hand rule:
a) JJ Thompson's discovery of the electron by measuring m/q
b) Hall effect showing that the charge carriers are electrons
c) mass spectrometer
Handed out RA 23.2, problems in magnetism, additional problems in magnetism
Asked students to do problems 1-4 in problems in magnetism sheet for tomorrow.
Showed several examples of using the right hand rule:
a) JJ Thompson's discovery of the electron by measuring m/q
b) Hall effect showing that the charge carriers are electrons
c) mass spectrometer
Handed out RA 23.2, problems in magnetism, additional problems in magnetism
Asked students to do problems 1-4 in problems in magnetism sheet for tomorrow.
Friday, May 9, 2008
Friday, May 9, 2008
Answered one question on the electric circuit problem sheet 1.
Introduction to magnetism.
Showed that a magnet exerts a stronger force on the paper clips than the Earth.
Dick Tracy - He who controls magnetism controls the universe.
Sprinkled iron filings on paper over magnets (used simple bar magnet and horseshoe magnet under plastic crate). Showed patterns. Just as electric charges affect space, so do magnets. The filings align along magnetic field lines. Talked about North and South poles of magnetics. Opposite poles attract, like poles repel.
Showed maps of declination for US and world. Declination is the deviation between magnetic north and geographical north. Note, since the north pole of a compass points north and opposite poles attract, the magnetic north is actually a south magnetic pole. Also mentioned magnetic dip.
Showed with demo of wire and compasses that currents create a magnetic field. Showed Right Hand rule for current carrying wires. Point the thumb of the right hand in the direction of conventional current and the fingers curl in the direction of the magnetic field. Magnetic field lines are circles around the current carrying wire. The magnetic field = uo * I/(2 * pi * r).
k = 1/(4 * pi* eo)
Students calculated sqrt (1/(uo *eo) to get c.
Currents create magnetic fields. Changing magnetic fields in coils of wires create currents. Demonstrated with wires and galvanometer with horseshoe magnet and then more dramatically with the magnets in the coil of wire. Therefore changing magnetic fields create currents.
Showed using TV that magnets affect charges. Showed using oscilloscope that when you move the magnet left and right, the dot moves up and down. When you move the magnet up and down, the dot moves right and left. Must work in 3-D to do magnetism.
Showed second Right Hand Rule. Point the fingers of the right hand in the direction of velocity, curl the fingers to the direction of the magnetic field. The thumb points in the direction of force on a positive charge. If the charge is negative, flip the direction.
F = q V X B
Went over several examples finding direction of force. If v and B are co-linear, or the charge is at rest (v = 0), then F = 0.
Another way of writing the magnitude of the force is F = q v B sin (theta)
Showed examples of forces of one wire on another. First wire sets up a magnetic field at the location of the second wire. That magnetic field affects the moving charges. Wires with currents in the same direction attract, opposite direction and they repel.
Showed split ring commutator example for a motor.
Handed out RA 23.1 due Monday.
Introduction to magnetism.
Showed that a magnet exerts a stronger force on the paper clips than the Earth.
Dick Tracy - He who controls magnetism controls the universe.
Sprinkled iron filings on paper over magnets (used simple bar magnet and horseshoe magnet under plastic crate). Showed patterns. Just as electric charges affect space, so do magnets. The filings align along magnetic field lines. Talked about North and South poles of magnetics. Opposite poles attract, like poles repel.
Showed maps of declination for US and world. Declination is the deviation between magnetic north and geographical north. Note, since the north pole of a compass points north and opposite poles attract, the magnetic north is actually a south magnetic pole. Also mentioned magnetic dip.
Showed with demo of wire and compasses that currents create a magnetic field. Showed Right Hand rule for current carrying wires. Point the thumb of the right hand in the direction of conventional current and the fingers curl in the direction of the magnetic field. Magnetic field lines are circles around the current carrying wire. The magnetic field = uo * I/(2 * pi * r).
k = 1/(4 * pi* eo)
Students calculated sqrt (1/(uo *eo) to get c.
Currents create magnetic fields. Changing magnetic fields in coils of wires create currents. Demonstrated with wires and galvanometer with horseshoe magnet and then more dramatically with the magnets in the coil of wire. Therefore changing magnetic fields create currents.
Showed using TV that magnets affect charges. Showed using oscilloscope that when you move the magnet left and right, the dot moves up and down. When you move the magnet up and down, the dot moves right and left. Must work in 3-D to do magnetism.
Showed second Right Hand Rule. Point the fingers of the right hand in the direction of velocity, curl the fingers to the direction of the magnetic field. The thumb points in the direction of force on a positive charge. If the charge is negative, flip the direction.
F = q V X B
Went over several examples finding direction of force. If v and B are co-linear, or the charge is at rest (v = 0), then F = 0.
Another way of writing the magnitude of the force is F = q v B sin (theta)
Showed examples of forces of one wire on another. First wire sets up a magnetic field at the location of the second wire. That magnetic field affects the moving charges. Wires with currents in the same direction attract, opposite direction and they repel.
Showed split ring commutator example for a motor.
Handed out RA 23.1 due Monday.
Thursday, May 8, 2008
Thursday, May 8, 2008
Went over questions from Problem Sheet 1.
Gave out quizzes on electric circuits.
Handed out extra credit resistor problems - due on Monday for Extra Credit.
For tomorrow, finish doing problems on Problem Sheet 1.
Gave out quizzes on electric circuits.
Handed out extra credit resistor problems - due on Monday for Extra Credit.
For tomorrow, finish doing problems on Problem Sheet 1.
Wednesday, May 7, 2008
Wednesday, May 7, 2008
Review of voltage, current, resistance, Ohm's Law, Power relationships.
Review of resistors in series and parallel - derived equations for finding equivalent resistance for series and parallel circuits.
Reviewed results of light bulbs from yesterday. 100 W bulb has lower resistance than 60 W light bulb but in series the 60 W light bulb will burn brighter.
Physiological Effects of Current lab/demo
Found dry and wet resistance of Tiffany and Travis.
Demonstrated and then discussed how to use voltmeters and ammeters and how to put them into circuits. Explained what would happen if you connected them incorrectly.
Assigned the remainder of problems from problem sheet 1 for homework.
Review of resistors in series and parallel - derived equations for finding equivalent resistance for series and parallel circuits.
Reviewed results of light bulbs from yesterday. 100 W bulb has lower resistance than 60 W light bulb but in series the 60 W light bulb will burn brighter.
Physiological Effects of Current lab/demo
Found dry and wet resistance of Tiffany and Travis.
Demonstrated and then discussed how to use voltmeters and ammeters and how to put them into circuits. Explained what would happen if you connected them incorrectly.
Assigned the remainder of problems from problem sheet 1 for homework.
Tuesday, May 6, 2008
Tuesday, May 6, 2008
Many students absent due to IB History test.
Went over RA 22.1
Introduced Ohm's Law: I = V/R
Showed how to find equivalent resistances for series (one after the other with a single path for current) and parallel (same potential difference across each element).
Showed demo of Christmas tree light hooked up in series and parallel. Investigated what happened to the brightness of the lights.
Derived P = I*V = I^2 *R = V^2/R
Talked about 60W and 100W light bulbs. Using them in parallel showed that the 100W light bulb has less resistance.
In series, the 60W light bulb would burn brighter since it has a higher resistance, would have a greater potential difference across it, and would dissipate more power.
Students worked problem 9 (combinations of resistors in series and parallel) in class. Assigned problems 1-8 (as well as 9 if they didn't finish) for homework.
Went over RA 22.1
Introduced Ohm's Law: I = V/R
Showed how to find equivalent resistances for series (one after the other with a single path for current) and parallel (same potential difference across each element).
Showed demo of Christmas tree light hooked up in series and parallel. Investigated what happened to the brightness of the lights.
Derived P = I*V = I^2 *R = V^2/R
Talked about 60W and 100W light bulbs. Using them in parallel showed that the 100W light bulb has less resistance.
In series, the 60W light bulb would burn brighter since it has a higher resistance, would have a greater potential difference across it, and would dissipate more power.
Students worked problem 9 (combinations of resistors in series and parallel) in class. Assigned problems 1-8 (as well as 9 if they didn't finish) for homework.
Monday, May 5, 2008
Monday, May 5, 2008
Went over Electrostatics test
Collected RA 22.1
Handed out summary of electrostatics and electric current
Started Hewitt video on electric current
Collected RA 22.1
Handed out summary of electrostatics and electric current
Started Hewitt video on electric current
Friday, May 2, 2008
Thursday, May 1, 2008
Thursday, May 1, 2008
Quiz on finding electric field between charged parallel plates. Students redid it if they didn't get on the first try.
Used laptops to connect to WebAssign. Students worked either alone or in pairs to do the WebAssign problems from Giancoli chapter 16, 17.
Test tomorrow on Electrostatics: Force, Electric Field, Electric Potential
Used laptops to connect to WebAssign. Students worked either alone or in pairs to do the WebAssign problems from Giancoli chapter 16, 17.
Test tomorrow on Electrostatics: Force, Electric Field, Electric Potential
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