__Overview__

The goal of this activity is to allow students to apply their knowledge of Ohm’s law to a more intuitive and visual system: water flowing through tubes. The total time for this activity is around 30 minutes. Students are assumed to be familiar Ohm’s law (V/R=I) where V is volts, R is resistance, and I is current, as well as the formula for calculating the resistance of a resistor (R=ρl/A). where p is resistivity in ohms/meter, l is length, A is area of the conductor.

The water/hose analogy for electricity is useful for explaining voltage, current, and power. In general terms, **charge** is water, **voltage** is the pressure of water, **current **is the flow of the water. **Power** is the total amount of water flowing in given time. You can have a small pipe with high pressure, or a large pipe with low pressure each passing the same amount of water. Increasing the height of the water reservoir increases the potential energy of the water (voltage). **Resistance** can be explained as the roughness of the width of the pipe.

Complete lesson plan: