/ I / the Phenomenon |
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Some objects can exert forces on other objects without even Being in contact.
[CER] DISCUSSION QUESTION:
Do force fields exist? Make a claim then gather evidence to support and justify your claim throughout this lesson. |
/ Ii / Investigate
/ iII / Level Up!
During this lesson you will learn more about the underlying forces that explain the variety of interactions we observed between objects.
✎Notes:
- Electric and magnetic (electromagnetic) forces can be attractive or repulsive, and their sizes depend on the magnitudes of the charges, currents, or magnetic strengths involved and on the distances between the interacting objects.
- Gravitational forces are always attractive.
- There is a gravitational force between any two masses, but it is very small except when one or both of the objects have large mass—for example, Earth and the sun.
- Long-range gravitational interactions govern the evolution and maintenance of large-scale systems in space, such as galaxies or the solar system, and determine the patterns of motion within those structures.
- Forces that act at a distance (gravitational, electric, and magnetic) can be explained by force fields that extend through space and can be mapped by their effect on a test object (a ball, a charged object, or a magnet, respectively).
/ IV / choose your path
NOVICE [+2 points]
Describe the evidence you have that force fields can exist between objects that are not in contact. ACCOMPLISHED [+3 points]
Using the video, "Scotch tape electrostatics" what do you think about the experimental design? Do you think this experimental design provides enough evidence that fields exist between objects that act on each other even though the objects are not in contact? Explain why or why not. |
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ADVANCED [+4 points]
Plan your own investigation to provide evidence that fields can exist between objects even though the objects are not in contact using the criteria below:
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MASTER [+6 points]
Plan and conduct your own investigation using the advanced and expert criteria above then evaluate your experimental design by assessing whether or not the data produced by your investigation can provide evidence that fields exist between objects that act on each other even though the objects are not in contact. |
/ V / Knowledge Check
A pith ball is a very small, lightweight object that picks up electric charge quite well. A charged pith ball works well to show the force between two electrically charged objects. If a glass rod is rubbed with silk, the silk rubs some electrons off the rod. The rod thus becomes positively charged.
Touching the positively-charged rod to two pith ball gives the balls each a small positive charge. Since like charges repel, the pith balls repel one another.
If an ebonite rod is rubbed with fur, the rod rubs some electrons off the fur. The rod thus becomes negatively charged and attracts the positively-charged pith balls. Apparatus:
Procedure:
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✓ MASTERY CHECK
National Research Council 2012. A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas. Washington, DC: The National Academies Press. https://doi.org/10.17226/13165
This site contains original content that may not be authorized for use by the creator and is legally used under the fair use principles section 107 of the Copyright Act of 1986 (17 U.S. Code § 107)
The official NGSS website. https://www.nextgenscience.org
PS2.B, MS-PS2-5
Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact. (Cause and Effect) [MS-PS2-5]
This site contains original content that may not be authorized for use by the creator and is legally used under the fair use principles section 107 of the Copyright Act of 1986 (17 U.S. Code § 107)
The official NGSS website. https://www.nextgenscience.org
PS2.B, MS-PS2-5
Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact. (Cause and Effect) [MS-PS2-5]