Identifying two forms of charge and the direction of the forces between them
Solving problems involving electric fields and Coulomb’s law
Identifying sign and nature of charge carriers in a metal
Important Vocabulary - Quizlet of Topic 5 Vocab
Charge
Electric field
Coulomb’s law
Balloon Electroscope: How many excess charges are on the balloon?
Goals:
Recap of free-body diagrams (FBD's) and basic forces
Combine the study of mechanics and E&M
Manipulation of quantities to arrive at final answer.
This is a photo of the same balloon in two positions.
Level 1 Resources
Static Electricity
Level 2 Resources
Conservation of Charge
Coulomb's Law Info
PIVOT Interactives
Exploring Electric Repulsion
Separating Charges:
Triboelectric Effect - Video
The Physics Classroom - Concept Builders
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Balloons and Static Electricity - Questions (Self-marking quiz)
Using the above information (and any other info you may find. Answer the following:
What measurements can be made?
What quantities can be determined?
On an atomic scale, what is happening in the metal ramp?
How many electrons are involved in the displacement of the balloon? (net)
Other Q’s you may have.
Please include the following in your answers to the questions:
Include the following:
Annotated (Add brief notes to a diagram or graph.) diagram of the set-up
Measurements that can be taken.
Suggest possible changes to the system that may affect the outcome.
Outline the assumptions can be made about the problem?
Describe possible relationships that may be present in the system.
Calculations that support an answer to why the balloon is attracted to the metal ramp.
Use the guide above to ensure you have a complete description of your findings. Be prepared to share your findings on an in-class board presentation from the JamBoard.
How can we quantify what is being stored?
Energy (stored as ??? transferred as ???)
Voltage (THE VOLTS MAY JOLT, )
Current (BUT IT'S THE MILLS. THAT KILL.)
Charges (can you count the imbalance?)
Electric Field (Which of the 4 variables can you quantify?)
Volts v. Amps (video)
Do Volts or Amps Kill? (video)
The following problems are typical of IB problems sets.
On the day of presentations, you will be asked to present your solution to a random problem. You will have 20 min in class to create your solution with your partner(s).
Group I - Two Electric Charge Ranking
Group II - Two Nonlinear Electric Charge Ranking
Group III - Coulomb's Law Q's #3
Group IV - Coulomb's Law PROBLEMS #1
Group V - Coulomb's Law PROBLEMS #3
Group VI - Coulomb's Law PROBLEMS #4
Shooting for a 6/7 - Complete the following for additional background info.
Separation of Charges (In class demo / At home video)
Follow the directions in class using the balloons and tinsel. (If you were not in class, watch this VIDEO).
Ask as many questions as possible about the activities (the physics of the demonstration, not the production).
Categorise your questions into two categories: Google-able and non-Google-able.
Find the answers to the google-able questions online.
Bring the non-Google-able questions to class.
Assignment of Positive (+) and Negative (-) Charges (At Home Activity)
Two Options
Physical Activity - Follow the instructions in document to the right - Sticky Tape Activity
Watch video of activity - much better to do in person.
Summarize your findings by answering the following questions:
E&M 1: Sticky Tape Activity (we can discuss answers in small groups during office hours.)
or
VdG Activities
A New Doo - What makes your hair do that doo?
DANCING BUBBLES - Blow soap bubbles at your VDG terminal. Describe the path they take and provide a possible explanation.
Spinning Needles - Using the term ION WIND, describe the motion of the three needles.
The VdG Generator creates charges up to 20 000V, knowing this explain the phrase: Volts jolt, current kills.