Looked at and analyzed data for Experiment #2 in the lab: The Falling Mass.

Interesting Notes about the data: (typical values are listed below.)

• A 1kg Mass Falls around 1.4m turning a generator that is connected to a resistor. ( A resistor converts voltage and current into heat.)
• The change in Potential energy is mgh = 14J
• Voltage across Resistor = 2.4V, Current through Resistor = 0.2A
• P = I*V = 0.48W
• The time it took the mass to fall 1.4 meters is approximately 5.1 seconds
• E =P*t = (0.48W)*(5.1) = 2.4J
• Efficiency = (Energy Out)/(Energy In) = (2.4J/14J) = 0.17
• 0.17 = 17% efficiency

Class Discussion: Where does the rest of the energy go?

• Heat
• Kinetic Energy in the Falling Mass
• Noise from the Generator

In order for the generator to turn, the mass must be falling. Therefore there will always be potential energy converted into some kinetic energy, therefore we can see that we can never have 100% efficiency.

With that in mind let us proceed into the:

Study of Thermodynamics.