MS - PS2.B (C) - Force Fields - ASSIGNED (CLF 3/6/2014)

Module: Applying Gravitational Forces

DCI: PS2.B (C) Forces that act at a distance (electric, magnetic, and gravitational) can be explained by fields that extend through space and can be mapped by their effect on a test object (a charged object, or a ball, respectively)

PE: 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.

[Clarification Statement: Examples of this phenomenon could include the interactions of magnets, electrically-charged strips of tape, and electrically-charged pith balls. Examples of investigations could include first-hand experiences or simulations.] [Assessment Boundary: Assessment is limited to electric and magnetic fields, and limited to qualitative evidence for the existence of fields.]

The ideas are: 

- Forces that act at a distance can be explained by fields

- These fields extend through space and can be mapped by their effect on a test object

Students will have to conduct investigations in the classroom, but we can evaluate experimental design easily on an assessment.  They can point out the evidence that will tell them that there are fields acting on objects, or they can point to a flaw in the experimental design. 

Possible Question Starters:
- Which of the following observations about a pair of interacting magnets would tell us that the a magnetic field exists between them?

- A student holds two strips of tape near each other and notices that the ends of each strip move closer towards one another.  Which of the following best explains this?