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Electricity, Magnetism and Waves
Physical Science Unit 5
3/23/15
• Entry Task
• Describe everything you know about electricity, magnetism and waves.
• HW Read pages 382-388, answer # 1-8 on page 388. Due Thursday 3/26/15
ORGANIZE, STAPLE and TURN IN SLUDGE!
• Rubric on top
• Daily Log
• Data Table (matrix on back please)
• Conclusion and Evaluation
Today’s Agenda
• Finish “Absolute Zero”
• Answer Q
• Next….
• MIT professor Dr. Lewin “What holds our world together”
• https://www.youtube.com/watch?v=Lx64cq0HeXY
• NOTES on First 30 minutes IN YOUR COMP BOOKS
3/23/15
• Exit Task
• Describe charges and how you could create an attraction between two objects based on charges.
• What charges would repel each other?
3/24/15
• Entry Task
• Define electric current, electric circuit and voltage.
• Review yesterday’s exit task.
Today’s Agenda
• Finish MIT lecture – 30 min – Take notes!
• Notes on Electricity – start today and finish tomorrow
3/24/15
• Exit Task
• Explain polarization of an atom or an object.
3/25/15
• Entry Task
• How are electrons related to electricity?
• http://www.energyquest.ca.gov/story/chapter02.html
Electricity
• A neat analogy to help understand these terms is a system of plumbing pipes. The
voltage is equivalent to the water pressure, the current is equivalent to the flow rate, and
the resistance is like the pipe size or water wheel.
• http://science.howstuffworks.com/environmental/437-green-gadgets-the-kill-a-watt-video.htm
• Opposite charges attract and same charges repel.
• unit of measurement for charge is the coulomb (C)
– one electron has a charge of 0.00000000000000000016 coulombs or 1.6 x 10 -19
Charge
Current
• comes from the motion of electrons
• is the rate at which electrons flow past a point on a circuit
– measured in units called amperes, or amps (A)
current
Voltage
• a measure of electric potential energy
• voltage is an electrical force
– measured in volts (V)
• a difference in voltage provides the energy that causes current to flow
Resistance
• the resistance to the flow of electrical current
– measured in ohms
• the resistance of electricity creates heat
Circuits
• current only flows when there is a complete and unbroken path, or a closed circuit
Electricity and Circuits (8:35)
http://www.youtube.com/watch?v=D2monVkCkX4&feature=related
• series circuit
– current can only take one path, so the current is the same at all points in the circuit
• parallel circuit
– the current can take more than one path
– each branch works independently
3/25/15
• Exit Task
• Explain the analogy of a water system and electrical circuit using the words: voltage, current and resistance.
3/26/15
• Entry Task
• Explain series circuit and parallel circuit.
• What is the difference?
• Trade and Grade homework
Today’s Agenda
• Watch 4 minutes of video.
• Phet simulations + Worksheet
• You will be working with the person seated next to you. PLEASE WRITE BOTH NAMES ON THE WORKSHEET.
• Decide who will be recorder for page 1 (F/B) and then you will switch recorders for page 2 (F/B).
Electricity and Circuits (8:35)
http://www.youtube.com/watch?v=D2monVkCkX4&feature=related
3/26/15
• Exit Task
• How did you prove today in PHET that electric current flowing in a wire creates a magnetic field around the wire? (HINT: what happened to the compass?)
3/27/15
• Entry Task
• Say Something Nice
Today’s Agenda
• Finish PHET part 2 – be sure you have switched recorders for this 2nd part.
• Finish packet by end of class
3/27/15
• Exit Task
• Trade and Grade
• Please turn in your entry/exit task sheet for the week.
3/30/15
• Entry Task
• How does a generator work? Please include copper coils and magnets in your explanation.
• https://www.youtube.com/watch?v=k7Sz8oT8ou0
• TODAY END OF CLASS: hand in comp books for grading.
• NOTE: I have graded all Sludge labs. TURN IT IN IF YOU HAVE NOT! Tutoring available M-Th 2:30-3:30
Today’s Agenda
• 10 minutes for PHET electricity – TURN IT IN!
• Read “Shake it up! The science behind induction”
• Write down pre-lab for Generator Lab
• If time, conduct lab.
Generator Lab: # of Coils vs Brightness
• Question: How does number of copper coils affect brightness of the LED light?
• Materials:
• 5 tube generators: 0 coils, 50 coils, 100 coils, 150 coils, 200 coils and LED bulb
• 10 neodymium magnets
• compass
• Write your hypothesis!
Procedure 1. Remove magnets from plastic tube. DO NOT SEPARATE or
DROP THEM – shatter easily. 2. Use the compass to determine the North and South pole of
the magnets. 3. Place the 10 magnets inside the 200 coil generator tube.
Cover either end with hands. 4. Shake the 200 coil generator tube 10x. NOTE: if it does not
light up, turn the magnets to the opposite pole. 5. Record which pole down made the LED bulb light up. 6. Record the brightness of the LED bulb on a scale of 1-10 with
10 being the brightest. 7. Repeat steps 2-4 for 2 more trials. 8. Repeat steps 2-5 except use the 150 coil generator, then the
100 coil generator, the 50 coil generator and finally the 0 coil.
9. For the experimental control condition, shake the tube without any coils to be certain no electricity flows.
Data Table # of Coils Trial 1 – relative
brightness (scale of 1-10)
Trial 2 – relative brightness (scale of 1-10)
Trial 3 – relative brightness (scale of 1-10)
Average – relative brightness
200 Coils N or S down?
150 Coils N or S down?
100 Coils N or S down?
50 Coils N or S down?
E.C.C.- 0 coils N or S down?
Analysis and Conclusion Questions
1. What is a complete circuit?
2. How could you tell when current was flowing?
3. What difference did the pole direction make?
4. Can you think of a way to tell which direction the current is flowing?
5. List the energy forms and transformations in the generator lab.
6. Besides increasing the # of coils, how else might you increase the brightness of the bulb?
7. Write a conclusion using RADDSS
3/30/15
• Exit Task
• What is your hypothesis? Use IF, THEN, BECAUSE…
• TODAY END OF CLASS: hand in comp books for grading.
3/31/15
• Entry Task
• Explain “the generator effect.” Hint: look at the standard on the board and recalled our entry task yesterday.
• DON’T FORGET!! Leave your comp books on the shelf at the end of class!!
• I will be grading “SA vs Time to Complete Chemical Reaction.”
• Worth 30 points – please have your rubric near the lab.
Today’s Agenda
• Write down pre-lab for Generator Lab
• Conduct lab.
• Complete Analysis and Conclusion Questions.
3/31/15
• Exit Task
• What can you conclude? How does # of coils affect brightness of LED?
• Write your conclusive statement!
• DON’T FORGET!! Leave your comp books on the shelf at the end of class!!
4/1/15
• Entry Task
• Do you think changing the number of magnets will affect the brightness of the bulb? Explain.
• Test TODAY!!!
• April Fools
• Quiz on Friday For reals…
Today’s Agenda
• Write down pre-lab for today’s lab: Generator Lab Part 2: # Magnets vs Brightness.
• If time, conduct the lab.
Generator Lab: # of Magnets vs Brightness
• Question: How does number of magnets affect brightness of the LED light?
• Materials:
• One tube generator
• 9 ceramic block magnets OR 6 neodymium magnets
• compass
• Write your hypothesis!
Procedure 1. Use the compass to determine the North and South
pole of the magnets. 2. Place the 9 magnets on the wire post inside generator
tube. Cover either end with hands – the wire post can go between your fingers. .
3. Shake the generator tube 10x. NOTE: if it does not light up, turn the magnets to the opposite pole.
4. Record which pole down made the LED bulb light up. 5. Record the brightness of the LED bulb on a scale of 1-10
with 10 being the brightest. 6. Repeat steps 2-4 for 2 more trials. 7. Repeat steps 2-5 except use 6 magnets, 3 magnets and 0
magnets. 8. For the experimental control condition, shake the tube
without any magnets to be certain no electricity flows.
Data Table # of Magnets Trial 1 – relative
brightness (scale of 1-10)
Trial 2 – relative brightness (scale of 1-10)
Trial 3 – relative brightness (scale of 1-10)
Average – relative brightness
9 magnets N or S down?
6 magnets N or S down?
3 magnets N or S down?
E.C.C.- 0 magnets N or S down?
Data Table # of Magnets Trial 1 – relative
brightness (scale of 1-10)
Trial 2 – relative brightness (scale of 1-10)
Trial 3 – relative brightness (scale of 1-10)
Average – relative brightness
6 neodymium magnets N or S down?
4 neodymium magnets N or S down?
2 neodymium magnets N or S down?
E.C.C.- 0 magnets N or S down?
Conclusion
• Write a conclusion using RADDSS –Restate and ANSWER the question –Data HIGH average –Data LOW average –Subtract to get range –Scientific Explanation of the results
• Please include a sentence for how we could improve the accuracy/validity of this experiment.
4/1/15
• Exit Task
• What would you like to investigate next regarding generators? Write your next investigative question!
• How does (independent variable) affect (dependent variable)?
4/2/15
• Entry Task
• What is an electromagnet?
• What would happen to a compass brought near an electromagnet? Why?
Today’s Agenda
• Demo of electromagnet. • Write the following down in your comp books: • ELECTROMAGNETS • Draw a diagram. • Q: How does # of coils affect strength of
electromagnet? • 10 coils picks up __________ paperclips. • 5 coils picks up __________ paperclips. • Write your CONCLUSIVE STATEMENT. • STUDY GUIDE FOR TOMORROW’s QUIZ.
4/2/15
• Exit Task
• Explain the “electromagnetic effect.” Hint: consider what you witnessed today and the 3rd standard on the board.
4/3/15
• Entry Task
• Say Something Nice
Today’s Agenda
• Review answers from Study Guide
• Take Quiz.
• Conversations with individuals regarding missing work to do over Spring Break.
4/3/15
• Exit Task
• Trade and Grade.
• Please turn in your entry/exit task sheets for the week.
• Have a GREAT SPRING BREAK!!
Today’s Agenda
• Another generator you could build at home:
• http://www.creative-science.org.uk/gensimple1.html
• How are magnets made? https://youtu.be/noGGcyPHtdI
• Faraday builds the first motor https://www.youtube.com/watch?v=yVDHKKTC4tA
4/13/15
• Entry Task
• Find and record definitions of: • Wave • Wavelength • Frequency • Amplitude • HOMEWORK: Read pages 613-618. Answer
#1,3,4,7,8,9 on page 619. Due Friday 4/17/15
Today’s Agenda
• A few students will be making up the Electricity Quiz
• Notes on Waves
• Pre-Lab for Slinky Wave Lab
24.2 What is a wave?
A wave is an oscillation that travels from one place to another.
If you poke a floating ball, it oscillates up and down.
The oscillation spreads outward from where it started.
24.2 Parts of a wave
You can think of a wave as a moving series of high points and low points.
A crest is the high point of the wave.
A trough is the low point.
24.2 Parts of a wave
The frequency of a wave is the rate at which every point on the wave moves up and down.
Frequency means “how often”.
24.2 Parts of a wave
The amplitude of a water wave is the
maximum height the wave rises above
the level surface.
24.2 Parts of a wave
Wavelength is the distance from any point on a wave to the same point on the next cycle of the wave.
The distance between one crest and the next crest is a wavelength.
24.2 The speed of waves
The speed is the distance traveled (one
wavelength) divided by the time it takes (one
period).
We usually calculate the speed of a wave by
multiplying wavelength by frequency.
24.2 Transverse waves
The oscillations of a transverse wave are
not in the direction the wave moves.
24.2 Longitudinal waves
The oscillations of a longitudinal wave are
in the same direction that the wave
moves.
• Question
How will the wave’s amplitude (5 cm, 10 cm, or 15 cm) affect the time it takes for the wave to travel 1.5 meters?
• Materials
– slinky
– stop watch
– ruler/meter stick
• Watch demonstration.
Slinky “Wave” Labs
• HYPOTHESIS
Write your own hypothesis. We will test 3 conditions of the MV: 5 cm amplitude, 10 cm amplitude, and 15 cm amplitude.
• PROCEDURE
– Identify VARIABLES
• Independent/manipulated variable:
• Dependent/responding variable:
– Students plan and write PROCEDURE:
• Numbered list of detailed steps to do the lab
• Every condition should be tested for 3 trials
CONDITION TIME for wave to travel 1.5 meters in SECONDS
Trial 1 Trial 2 Trial 3 Average
Experimental Control Condition 0 cm amplitude
Condition 1 5 cm amplitude
Condition 2 10 cm amplitude
Condition 3 15 cm amplitude
4/13/15
• Exit Task
• What is height of the wave most like: frequency, amplitude or wavelength? Explain.
4/14/15
• Entry Task
• Write down your hypothesis for the slinky lab.
Today’s Agenda
• Finish notes and data table. • Write your procedure, include:
– A diagram of set-up, including how to measure amplitude
– Controlled variables (stay the same every trial) – 3 trials per condition – ECC – no amplitude
• Get approval of your procedure! • Conduct Lab – you’ll need 5 squares of space. • Write a conclusion using RADDSS.
4/14/15
• Exit task
• What can you conclude? How does amplitude affect the time it takes for the wave to travel 1.5 meters?
• REMINDER: Homework due FRIDAY! • Check lists (near library) of classrooms for
Wed/Thurs – YES, you should be there both days for registration work!
4/15/15 – Periods 1,2,3 and 4/16/15 – Periods 4,5,6
• Entry Task
• How do you think the amount of coils pulled into a wave pulse will affect the time it takes for a longitudinal wave to travel 1.5 meters?
• We will test 5 coils, 10 coils, 15 coils
• WRITE DOWN YOUR HYPOTHESIS.
Today’s Agenda
• Finish RADDSS conclusions for the last lab. Q: “How does amplitude affect time for a wave to travel 1.5 meters?”
• Write pre-lab, procedure and data table for next investigation.
• Conduct next investigation.
USE RADDSS to write conclusions
• R – restate the question and… • A – answer the question conclusively! Explain the
effect of the MV on the RV. • DHIGH – write out the highest results from the data
table and say which MV condition caused it. • DLOW – write out the lowest results from the data
table and say which MV condition caused it. • S – subtract to give range of data. • S – give a scientific explanation for the trend in
the data.
• Question
• How does the amount of coils (5 coils, 10 coils, or 15 coils) pulled into a wave pulse affect the time it takes for a longitudinal wave to travel 1.5 meters?
• Materials – slinky
– stop watch
– ruler/meter stick
• Watch demonstration.
Slinky “Wave” Labs
• HYPOTHESIS
Write your own hypothesis.
• PROCEDURE
– Identify VARIABLES
• Independent/manipulated variable:
• Dependent/responding variable:
– Students plan and write PROCEDURE
– (hint – just copy your last procedure and modify a few things to match the new MV:
– A diagram of set-up, including which coils to use to make the wave pulse.
– Controlled variables (stay the same every trial)
– 3 trials per condition
– ECC – no coils
CONDITION TIME for wave to travel 1.5 meters in SECONDS
Trial 1 Trial 2 Trial 3 Average
Experimental Control Condition 0 coils
Condition 1 5 coils
Condition 2 10 coils
Condition 3 15 coils
Today’s Agenda
• Write your procedure, include: – A diagram of set-up, including how to measure
amplitude
– Controlled variables (stay the same every trial)
– 3 trials per condition
– ECC – no amplitude
• Get approval of your procedure!
• Conduct Lab – you’ll need 5 squares of space.
• Write a conclusion using RADDSS.
4/15/15 – Periods 1,2,3 and 4/16/15 – Periods 4,5,6
• Exit Task
• What can you conclude? How does the # of coils affect the time it takes for a longitudinal wave to travel 1.5 meters?
• REMINDER: HOMEWORK DUE FRIDAY!!
4/17/15
• Entry Task
• Say Something Nice
• Trade and Grade HW
Today’s Agenda
• Get back your Unit 5 electricity quiz – discuss. • You may complete reflections in TUTORING in I-2 on M-
TH from 2:30 to 3:30. • NOTE: Both conclusions for both Slinky Labs Should
now be complete! At least one will be graded. • Rest of class – last physical wave activity: “Slinky Wave
Lab with PHET simulation” • Work with a partner. Each table group will need to
share a slinky. • For the PHET simulation, you’ll need to check out a
laptop.
4/17/15
• Exit Task
• Trade and Grade
