Phenomenon: When your hands are cold, you can try rubbing them together. This can cause them to increase in temperature.

we will be answering the Big Question: Why do our hands warm up when we rub them together? please do the following:

1. Tell a story with a beginning, middle, and end
2. Construct a Timeline for an Energy Interaction Diagram where you define the initial state (both qualitatively and with indicator(s) as variables) and the final state (both qualitatively and with indicator(s) as variables).

GRAPHICAL REPRESENTATION The Energy-Interaction Diagram This is a generic example involving two physical systems (Physical Thing #1 and Physical Thing #2), three Energy Systems, and energy being added to the system as heat: Identification of beginning and end of interval: Beginning End Description Description initial conditions final conditions physical system physical thing 1 physical thing 2 heat Q physical thing 1 indicator a indicator a indicator b I El,a 1 El,b I E2,a ai Or = of = bi = of bf = ( + ) (- ) ( + ) (- ) Q = AEl,a + AEl,b + AE2,aEnergy Systems and their Indicators Energy Systems related to Thermal and Chemical Processes temperature T of substance A Ethermal = mCpAT Ethermal m: mass of substance AT = TJ - Ti Cp: Specific Heat of substance mass m of higher phase A Ephase = AmHp Ephase Am: change in mass of substance in "higher" phase Am = my - mi Hp: Heat of (Phase Change) Energy Systems related to Mechanical Processes height y distance x AP Eelastic = kAx2 above y=0 AP Egravitational = mgy from equilibrium k: spring constant PEgravitational m: mass of object PEelastic The spring's equilibrium position is equal to the spring's natural rest Ay = yf - yi g: gravitational constant, 9.8 m/s Ax2 = 27 -27 position. The mass is not attached. Spatial orientation is irrelevant. AP Espring-mass = KAx2