Reviewed reflection and refraction.
Asked what value students got for the index of refraction of light in water. Used this value to calculate the speed of light in water.
Showed again that when going from fast to slow the wave bends towards the normal. When going from slow to fast, the wave bends away from the normal.
In going from slow to fast, as you increase the angle of incidence, you reach a point where the angle of diffraction is 90 deg. If you increase the angle of incidence any more, you do not get a refracted ray, instead you get total internal reflection. Demonstrated total internal refraction with laser and optic fiber.
Defined and calculated the critical angle.
Other examples of refraction are mirages and the fact that the Sun is already really well below the horizon when you see it setting.
Talked about diffraction - bending or spreading of a wave as it passes through an opening or around a barrier. Sent student out into hallway. They can hear you but not see you. Calculated the wavelength of the sound wave and compared it to the wavelength of light. Longer wavelengths are diffracted more. That is why you can hear around corners but not see around corners.
Used circular pattern overheads to demonstrated diffraction and interference.
Young's double slit diffraction experiment was used to measure the wavelength of light. Described the set-up and math for the experiment.
We used a double slit to measure the wavelength of laser light.
I then showed how to measure the wavelength using a ruler. We got a value of 590 nm.
Handed out worksheet on reflection and refraction.
Thursday, February 26, 2009
Wednesday, Feb 25, 2009
Collected RA 18.1
Talked about reflection and refraction.
Reflection - for specular reflection, angle of incidence = angle of reflection. Defined the normal. Did problem of viewing self in mirror - how much mirror do you need. Demo of how much of you you can see vs how far away you are.
Mentioned diffuse reflection.
Refraction - Bending of a wave as it goes from one medium into another in which it travels at a different speed. Demo in hallway using people wave.
Sketched pictures of the demo on the board defining wave front and ray. Show that when going from fast to slow, the ray bends towards the normal.
Introduced Snell's Law - n1 * sin(theta1) = n2 * sin(theta2)
n is the index of refraction. For light n = c/v
For other waves, sin(theta1)/v1 = sin(theta2)/v2
Students did lab on measuring the speed of sound using the tube.
Lab write-up due Friday: Include Name, Partners, Date, Name of Lab
Brief description of lab, data table, measured speed of sound.
Calculate the the accepted value and compare measured to accepted for that temperature.
Students also did the Snell's Law lab in which they measured the index of refraction of water using the semi-circular containers. Students measured the angles of incidence and refraction and then used the laptops with Excel to make a data table and plot sin(angle of incidence)/sin (angle of refraction). The slope gave the index of refraction of water assuming the index of refraction in air is 1.
Write-up: Name, Partners, Date, Name of Lab
Brief description of lab, data table, graph from Excel, Conclusion.
Both lab write-ups are due on Friday
Talked about reflection and refraction.
Reflection - for specular reflection, angle of incidence = angle of reflection. Defined the normal. Did problem of viewing self in mirror - how much mirror do you need. Demo of how much of you you can see vs how far away you are.
Mentioned diffuse reflection.
Refraction - Bending of a wave as it goes from one medium into another in which it travels at a different speed. Demo in hallway using people wave.
Sketched pictures of the demo on the board defining wave front and ray. Show that when going from fast to slow, the ray bends towards the normal.
Introduced Snell's Law - n1 * sin(theta1) = n2 * sin(theta2)
n is the index of refraction. For light n = c/v
For other waves, sin(theta1)/v1 = sin(theta2)/v2
Students did lab on measuring the speed of sound using the tube.
Lab write-up due Friday: Include Name, Partners, Date, Name of Lab
Brief description of lab, data table, measured speed of sound.
Calculate the the accepted value and compare measured to accepted for that temperature.
Students also did the Snell's Law lab in which they measured the index of refraction of water using the semi-circular containers. Students measured the angles of incidence and refraction and then used the laptops with Excel to make a data table and plot sin(angle of incidence)/sin (angle of refraction). The slope gave the index of refraction of water assuming the index of refraction in air is 1.
Write-up: Name, Partners, Date, Name of Lab
Brief description of lab, data table, graph from Excel, Conclusion.
Both lab write-ups are due on Friday
Tuesday, Feb 24, 2009
Handed back and went over SHM test
Reviewed characteristics of waves.
Showed oscilloscope demo with frequency generator. Long wavelengths produce low pitch, low frequency sounds. Short wavelengths produce high frequency, high pitch sounds. Showed the same with the pull-a-tune. The longer bar produces a longer wavelength wave and a lower note.
Students did slinky lab in hallway and also used the Vernier equipment to measure the speed of sound in air using the singing rods.
Handed out RA 18.1 due tomorrow.
Reviewed characteristics of waves.
Showed oscilloscope demo with frequency generator. Long wavelengths produce low pitch, low frequency sounds. Short wavelengths produce high frequency, high pitch sounds. Showed the same with the pull-a-tune. The longer bar produces a longer wavelength wave and a lower note.
Students did slinky lab in hallway and also used the Vernier equipment to measure the speed of sound in air using the singing rods.
Handed out RA 18.1 due tomorrow.
Friday, Feb 20, 2009
Reviewed for SHM test. Answered any questions from worksheet. There weren't very many questions.
Started lecturing on waves.
Two types of waves - mechanical and electromagnetic
Waves can also be classified as longitudinal or transverse.
Used slinky to show features of each wave and also to show the relationship between frequency, energy, and wavelength.
Introduced the equation, v = f*wavelength
Found wavelengths of AM and FM radio waves. Wavelength of microwave is about 1 ft to fit inside the box in kitchen.
Test tomorrow on SHM
Started lecturing on waves.
Two types of waves - mechanical and electromagnetic
Waves can also be classified as longitudinal or transverse.
Used slinky to show features of each wave and also to show the relationship between frequency, energy, and wavelength.
Introduced the equation, v = f*wavelength
Found wavelengths of AM and FM radio waves. Wavelength of microwave is about 1 ft to fit inside the box in kitchen.
Test tomorrow on SHM
Wednesday, February 18, 2009
Wednesday, Feb 18, 2009 - Block 3
Class started slowly with several students out giving blood.
Handed back RA 11.1 and asked if there were any questions. I graded the RA part out of 10 and assigned a grade for the problem part. There were 5 answers so I graded it out of 5.
Reviewed and finished problem of block bobbing in water.
Drew sketches of x, v, and a for SHM and showed that the slope of the displacement gives the velocity and the slope of the velocity gives the acceleration.
Covered energy in SHM. Showed that the elastic PE is given by 1/2 k x^2.
E total = 1/2 k x^2 + 1/2 m v^2 = 1/2 k A^2 = 1/2 m vmax^2
Drew sketches of E vs x.
Students calculated the value of x for which KE = elastic PE.
Did problem of SHM with tunnel through the Earth. Showed that the period is 84 min so that you get from one side to the other in 42 min.
Finished class by describing the IB lab - What are the factors that affect the period of a pendulum.
The design part must be done individually and is due on Friday. After that, students may work with a partner for the data collection. I instructed the students to think about using the Vernier lab equipment for data collection. Students will have to design their own pendulums.
Asked students to continue working on the remainder of the problems on the SHM problem sheet.
Test early next week.
Spring constant lab due tomorrow.
Handed back RA 11.1 and asked if there were any questions. I graded the RA part out of 10 and assigned a grade for the problem part. There were 5 answers so I graded it out of 5.
Reviewed and finished problem of block bobbing in water.
Drew sketches of x, v, and a for SHM and showed that the slope of the displacement gives the velocity and the slope of the velocity gives the acceleration.
Covered energy in SHM. Showed that the elastic PE is given by 1/2 k x^2.
E total = 1/2 k x^2 + 1/2 m v^2 = 1/2 k A^2 = 1/2 m vmax^2
Drew sketches of E vs x.
Students calculated the value of x for which KE = elastic PE.
Did problem of SHM with tunnel through the Earth. Showed that the period is 84 min so that you get from one side to the other in 42 min.
Finished class by describing the IB lab - What are the factors that affect the period of a pendulum.
The design part must be done individually and is due on Friday. After that, students may work with a partner for the data collection. I instructed the students to think about using the Vernier lab equipment for data collection. Students will have to design their own pendulums.
Asked students to continue working on the remainder of the problems on the SHM problem sheet.
Test early next week.
Spring constant lab due tomorrow.
Tuesday, Feb 17, 2009 - Block 3 IB Physics 2
Lectured on SHM
Talked about radian measurements, angular frequency, and related linear velocity to angular velocity.
Showed demo with turntable and related SHM to Uniform Circular Motion.
Derived the equations of motion for SHM from the projections of Uniform Circular Motion.
If Newton's 2nd Law can be written in the form: a = - C * x, then you can Zap (2) it to get w^2 = C, and find the frequency, period, and equations of motion.
Did several examples using combinations of springs. Started example of block bobbing in the water.
Handed out worksheet on SHM problems and asked students do to 1,2,3,4, and 6 for homework.
Talked about radian measurements, angular frequency, and related linear velocity to angular velocity.
Showed demo with turntable and related SHM to Uniform Circular Motion.
Derived the equations of motion for SHM from the projections of Uniform Circular Motion.
If Newton's 2nd Law can be written in the form: a = - C * x, then you can Zap (2) it to get w^2 = C, and find the frequency, period, and equations of motion.
Did several examples using combinations of springs. Started example of block bobbing in the water.
Handed out worksheet on SHM problems and asked students do to 1,2,3,4, and 6 for homework.
Friday, February 13, 2009
Friday, Feb 13, 2009 - Block 3
Students finished spring constant lab.
Explained how to use the F4 key in Excel to fix a cell in an equation.
Lab write-up is due next Thursday.
Explained how to use the F4 key in Excel to fix a cell in an equation.
Lab write-up is due next Thursday.
Thursday, Feb 12, 2009 - Block 3
Collected Oleic Acid Lab write-ups
Handed out IB Internal Assessment Guidelines and went over the Design, Data Collection and Presentation, and Results sections.
Went over spring constant lab. Asked students how they might approach it.
Instead of using a stopwatch and ruler, students will use the Vernier Motion Detector.
Explained how to collect the data for both the static and dynamic methods.
This lab will concentrate on the Data Collection and Presentation, and Results parts of the IB Internal Assessment.
Lab write-up
Static Method: I want a brief description of how students collected the data.
Show data tables complete with headers and labels.
Use Excel to create a graph
Use the Linest function to determine the uncertainty in the slope.
In the calculations section, explain and give a sample calculation for each type of calculation. Explain how you get the various quantities.
Dynamic Method: Again give a brief description of how you collected the data.
Show data tables complete with headers and labels.
Figure out what to graph to get a linear relationship
Use Excel to create a graph but this time do not force the line to go through the origin. Find the x-intercept which gives the correction factor for the mass of the spring.
Use linest to find the slope, uncertainty in slope, y-intercept, and uncertainty in y-intercept.
Determine the spring constant and its uncertainty.
Calculation section - explain and give a sample calculation for each type of calculation. Explain how you get the various quantities.
In the results section, clearly state the results along with their uncertainties. Compare and comment on the two methods. Discuss weaknesses in the two methods. Describe ways in which the procedure could be improved.
Determine the effective spring constants for combinations of springs and describe the method used to do this.
Answer the questions at the end of the lab explaining in your answer what it is you are answering.
Students worked in groups of two.
There was only one spring per group so they had to share for Part 3 of the lab.
Not all lap-tops had Logger Pro 3.5 on them
Students did not finish so I told them they could finish tomorrow.
I collected RA 11.1
Handed out IB Internal Assessment Guidelines and went over the Design, Data Collection and Presentation, and Results sections.
Went over spring constant lab. Asked students how they might approach it.
Instead of using a stopwatch and ruler, students will use the Vernier Motion Detector.
Explained how to collect the data for both the static and dynamic methods.
This lab will concentrate on the Data Collection and Presentation, and Results parts of the IB Internal Assessment.
Lab write-up
Static Method: I want a brief description of how students collected the data.
Show data tables complete with headers and labels.
Use Excel to create a graph
Use the Linest function to determine the uncertainty in the slope.
In the calculations section, explain and give a sample calculation for each type of calculation. Explain how you get the various quantities.
Dynamic Method: Again give a brief description of how you collected the data.
Show data tables complete with headers and labels.
Figure out what to graph to get a linear relationship
Use Excel to create a graph but this time do not force the line to go through the origin. Find the x-intercept which gives the correction factor for the mass of the spring.
Use linest to find the slope, uncertainty in slope, y-intercept, and uncertainty in y-intercept.
Determine the spring constant and its uncertainty.
Calculation section - explain and give a sample calculation for each type of calculation. Explain how you get the various quantities.
In the results section, clearly state the results along with their uncertainties. Compare and comment on the two methods. Discuss weaknesses in the two methods. Describe ways in which the procedure could be improved.
Determine the effective spring constants for combinations of springs and describe the method used to do this.
Answer the questions at the end of the lab explaining in your answer what it is you are answering.
Students worked in groups of two.
There was only one spring per group so they had to share for Part 3 of the lab.
Not all lap-tops had Logger Pro 3.5 on them
Students did not finish so I told them they could finish tomorrow.
I collected RA 11.1
Wednesday, Feb 11, 2009 - Block 3
We went to the computer lab and students did the Excel Spreadsheet Exercise. This was an improved version which included error bars and the use of the LINEST function.
Students did all parts of the exercise including the parts dealing with finding uncertainty using the Min-Max Method and the Method of Relative Uncertainty.
When done, students could work on redoing their uncertainty homework or on the Oleic Acid Lab write-up
Students did all parts of the exercise including the parts dealing with finding uncertainty using the Min-Max Method and the Method of Relative Uncertainty.
When done, students could work on redoing their uncertainty homework or on the Oleic Acid Lab write-up
Tuesday, Feb 10, 2009 - Block 3
Went over RA 10, RA 11.2
Started lecture on SHM
Did not get very far but did discuss spring constants.
Started lecture on SHM
Did not get very far but did discuss spring constants.
Monday, Feb 9, 2009 - Block 3
Collected RA 11.2
Handed out RA 11.1
Students did Oleic Acid Lab
Write-up is due Thursday.
Handed out RA 11.1
Students did Oleic Acid Lab
Write-up is due Thursday.
Friday, February 6, 2009
Friday, Feb 6, 2009 - Block 3 - IB Physics 2
Collected RA 10
Asked if there were any questions on the BB pancake lab. Most students liked being able to check their answers with the computer program and be able to rework them if their answers were not correct - and not have to hand in a lab write-up.
Told students that the Pendulum Lab will be postponed until Friday since I was able to book the computer lab for Wednesday.
Showed Hewitt video on Scaling. Handed out RA 11.2.
Gave students time to work on RA 11.2 in class.
If they don't finish it, finish it for homework and hand in on Monday.
In addition, the homework for Monday is to do the problems on the uncertainty worksheet. Students can put their answers on the excel spreadsheet and hand that in.
Handed out Oleic Acid Lab sheet. Students will do this lab on Monday.
Asked if there were any questions on the BB pancake lab. Most students liked being able to check their answers with the computer program and be able to rework them if their answers were not correct - and not have to hand in a lab write-up.
Told students that the Pendulum Lab will be postponed until Friday since I was able to book the computer lab for Wednesday.
Showed Hewitt video on Scaling. Handed out RA 11.2.
Gave students time to work on RA 11.2 in class.
If they don't finish it, finish it for homework and hand in on Monday.
In addition, the homework for Monday is to do the problems on the uncertainty worksheet. Students can put their answers on the excel spreadsheet and hand that in.
Handed out Oleic Acid Lab sheet. Students will do this lab on Monday.
Thursday, February 5, 2009
Thursday, Feb 5, 2009 - Block 3
Told students that next Wednesday I plan to have them do a major IB lab - what are the various factors that affect the period of a pendulum? They will have to think of how to do this using the Vernier equipment.
Asked if there were any questions on the IB Physics 1 review problems. There were none.
Went over uncertainties. Students measured length and width of a table top and estimated the uncertainties in each measurement.
Calculated the perimeter and its uncertainty. If you add or subtract quantities, you ADD the absolute uncertainty to get the uncertainty in the result.
After you get the uncertainty, this determines how you display your result. You can have AT MOST 2 sig figs in the uncertainty and then the number of decimal places in the uncertainty is the same as the number of decimal places in the result.
Showed how to calculate the area and uncertainty in the area using the min-max method and the method of relative uncertainty.
Students did the BB Pancake Lab.
I demonstrated how to use an micrometer so they could actually measure the diameter of the BB.
I set up a computer with an Excel spreadsheet so they could input their data table and check their answers with uncertainty.
Handed RA 10 due tomorrow. Handed out a worksheet on uncertainties due on Monday. Along with the worksheet I handed out the print of an excel program for them to input their answers.
Asked if there were any questions on the IB Physics 1 review problems. There were none.
Went over uncertainties. Students measured length and width of a table top and estimated the uncertainties in each measurement.
Calculated the perimeter and its uncertainty. If you add or subtract quantities, you ADD the absolute uncertainty to get the uncertainty in the result.
After you get the uncertainty, this determines how you display your result. You can have AT MOST 2 sig figs in the uncertainty and then the number of decimal places in the uncertainty is the same as the number of decimal places in the result.
Showed how to calculate the area and uncertainty in the area using the min-max method and the method of relative uncertainty.
Students did the BB Pancake Lab.
I demonstrated how to use an micrometer so they could actually measure the diameter of the BB.
I set up a computer with an Excel spreadsheet so they could input their data table and check their answers with uncertainty.
Handed RA 10 due tomorrow. Handed out a worksheet on uncertainties due on Monday. Along with the worksheet I handed out the print of an excel program for them to input their answers.
Wednesday, Feb 4, 2009 - Block 3
Set up various labs. Explained and demonstrated several of them to students.
Hoped students would try them and learn how to use the various probes.
Hoped students would try them and learn how to use the various probes.
Tuesday, February 3, 2009
Tuesday, Feb 3, 2009 - Block 3
Collected Parent notification forms and signed syllabus forms.
Checked for book covers.
Asked if there were any questions on the review problem sheet. Very few students even attempted the problems.
Took students to computer lab, gave them Quia user names and passwords and had them explore my Quia site. Also had them access the Chris Hamper site and try some of those problems.
Came back to the classroom with about 25 minutes left. Students worked on problem sheet.
Tomorrow we will review Vernier equipment. Thursday we will start new material.
Checked for book covers.
Asked if there were any questions on the review problem sheet. Very few students even attempted the problems.
Took students to computer lab, gave them Quia user names and passwords and had them explore my Quia site. Also had them access the Chris Hamper site and try some of those problems.
Came back to the classroom with about 25 minutes left. Students worked on problem sheet.
Tomorrow we will review Vernier equipment. Thursday we will start new material.
Monday, February 2, 2009
Monday, Feb 2, 2009 - Block 3
Got textbooks
Put name in text books.
Bring covered textbooks to class tomorrow for 10/10 points.
Handed out student profile. Students put them in bin when done
Handed out two copies of parent notification form. Bring one back tomorrow for another 10 points
Went over course expectation form. Bring back signed form for 5/5
Handed out list of IB Physics 1 topics. Went over main ideas. Didn't go so well. Handed out problem sheet with 10 minutes left in class. Asked students to try them or find out where the difficulties for tomorrow.
Tomorrow we will go to the computer lab 448 and work on Quia problems.
Put name in text books.
Bring covered textbooks to class tomorrow for 10/10 points.
Handed out student profile. Students put them in bin when done
Handed out two copies of parent notification form. Bring one back tomorrow for another 10 points
Went over course expectation form. Bring back signed form for 5/5
Handed out list of IB Physics 1 topics. Went over main ideas. Didn't go so well. Handed out problem sheet with 10 minutes left in class. Asked students to try them or find out where the difficulties for tomorrow.
Tomorrow we will go to the computer lab 448 and work on Quia problems.
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