Objectives1. State the three law of thermodynamics2. Describe how Specific Heat capacity affects our earth’s climate
Laws of Thermodynamics1. First law states: a. When heat flows in or out of a system it is being neither created or destroyed b. It only transfers to a different place
Laws ofThermodynamics2. Second Law states: a. Heat flows from a hot to a cold substance b. Has to be forced to move the opposite direction
Laws ofThermodynamics3. Third Law states: a. No system can reach absolute zero What is absolute zero? How do we know where it is at if we can’t reach it?
Specific Heat Capacity1. Heat is thermal energy in motion2. Heat is measured = Joules/ Calories
Specific Heat Capacity3. Different substance = different capacities for storing thermal energy a. Require different amounts of thermal energy to raise temperature
Specific Heat Capacity4. Specific Heat Capacity: quantity of heat required to change the temperature of a unit mass by 1 degree a. Measure of thermal inertia b. Matters ability to resist a change in temperature
Higher specific heat – stronger ability to resist changeLower specific heat – low ability to resist change
Specific Heat Capacity5. Which has a higher specific heat capacity, water or sand? In other words which takes longer to warm in sunlight (or longer to cool at night?)
Specific Heat Capacity6. Waters specific heat capacity: a. Higher capacity for storing energy b. Absorbs a great quantity of heat for small rises in temperature c. Takes much longer to cool, resistant to loosing thermal energy
Specific Heat Capacity d. Water’s specific heat changes the world’s climate i. Currents carry warmer water to Europe’s west coast keeping it warmer than the cool coast’s of Canada ii. Islands and peninsula’s do not have extreme temperatures
7. Bermuda is close to North Carolina, but unlike North Carolina, it has a tropical climate year round. Why?
Agenda Bell Work• Review 6 degrees and • Pick up Crossword HW Puzzle from front desk• Notes: Thermal • Complete Expansion• Heat Transfer Project
Thermal expansion b. When you can’t loosen a metal lid on a glass jar, why is it that you stick it under hot water to help you out?
Thermal Expansion2. Water’s Thermal expansion a. Expands when heated b. Between 0 and 4 degrees water particles contracts becoming more dense before freezing
Themal Expansion a. If you heat water at zero degrees it actually contracts as the ice crystals start to collapse before it will expand at 4 degrees
Themal Expansion3. When solid ice forms volume increases because of the ice crystals
ThermalExpansion a. Since ice is less dense it floats on bodies of water b. Water at zero degrees is less dense as well and stays near the tops c. Water at four degrees is more dense and will settle at the bottom keeping organisms warm all winter