duction: When an electrical potential exists in a circuit, a current may flow. Current is the flow of electrons in a circuit. Resistance in the circuit slows the flow of the electrons, reducing the current in the circuit. We will use the mathematical form of Ohm's Law frequently when we investigate electric current and circuits later in this unit. Additional Material Needed: Clean Drinking Straw Procedure Part I Wire Resistance: VISIT THE SITE: https://phet.colorado.edu/en/simulation/resistance-in-a-wire Blow through the drinking straw. Cut the drinking straw in half and blow through a half-straw. Describe the effect of length on ease to blow air through the straw. _________________________________________ Cut the halves again in half. With the four pieces, blow through one, then blow through all four made into a larger, square-shaped straw. Describe the effect of straw size (diameter) on ease to blow air through the straw