100 likes | 304 Vues
Intro to Thermal Energy & Matter. Heat, Temperature, Thermal Energy How are they different? How are they the same? KNOW YOUR DEFINITIONS!!!!. Energy. The ability to move or change matter Thermal Energy : the energy associated with movement of the microscopic particles that make up an object.
E N D
Intro to Thermal Energy & Matter Heat, Temperature, Thermal Energy How are they different? How are they the same? KNOW YOUR DEFINITIONS!!!!
Energy • The ability to move or change matter • Thermal Energy: the energy associated with movement of the microscopic particles that make up an object
Heat • HEAT is the transfer of thermal energy from one object to another because of a temperature difference • Heat flows spontaneously from objects with high temperatures to objects with low temperatures
Temperature • TEMPERATURE measures the average kinetic energy of the particles in an object • Cold Temp → Less Motion • High Temp → More Motion
Heat & Temperature • Heat flows from objects with high temperatures to objects with low temperatures • WHY? Explain using picture to right After a collision, things that are going fast (high temp) end up traveling slower Things that were traveling slower (low temps) end up traveling faster
THERMAL ENERGY • The total amount of motion of the particles that make up an object • The total damage that can be done • Thermal energy depends on • Mass • Temperature • State of Matter
How is Thermal Energy different from Temperature? Both the bucket and the cup have the same temperature (their particles move the same speed), but the bucket has more ability to do damage (thermal energy) due to its large size While the sparks have a very high temp (the particles are moving very fast), there are so few of them that the amount of damage (thermal energy) is relatively small
Thermal Expansion & Contraction • Based on the motion of the particles as the temperature changes, the volume of an object will change • Higher temp → Increased Motion → Larger Volume
Thermal Expansion Solids, Liquids, and Gases have very different volumes because the particles move at very different speeds A cold balloon has a much smaller volume than a warm balloon
Applications of Thermal Expansion The expansion of water and gases in soil causes cracks to form in dry, hot ground Expansion joints on bridges prevent thermal expansion from destroying the bridge A bimetallic strip has two sides that expand and contract at different rates, which causes the strip to “bend”