TESTING INVESTIGATION: RESISTIVITY OF PLAY-DOH
GIVEN: Container of Play-Doh, voltage source, voltmeter, ammeter, ruler, 2 alligator wires and nails
TASK:
a. Determine the relationship between resistance and length.
b. Determine the relationship between resistance and cross-sectional area.
POSTER: Multiple representations should include:
a. graphical representation of acquired data for both investigations
b. mathematical representation relating resistance to length and cross-sectional area.
c. determination of resistivity
EXTENSION:
Connect the concepts to a model of an axon in a neuron (biology).
AP PHYSICS 1 and 2
Essential Knowledge 1.E.2: Matter has a property called resistivity.
a. The resistivity of a material depends on its molecular and atomic structure.
b. The resistivity depends on the temperature of the material.
Essential Knowledge 4.E.4: The resistance of a resistor, and the capacitance of a capacitor, can be understood from the basic properties of electric fields and forces, as well as the properties of materials and their geometry.
a. The resistance of a resistor is proportional to its length and inversely proportional to its cross-sectional area. The constant of proportionality is the resistivity of the material.
c. The current through a resistor is equal to the potential difference across the resistor divided by its resistance.