Vocabulary

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Absolute zero is the lowest possible temperature that a substance can have. At absolute zero, the kinetic energy of the molecules is at a minimum.

Calorie: 1 calorie will raise 1 gram 1 degree Celsius. 1 calorie = 4.186 joules.

Condensation is the opposite of evaporation. It occurs when a gas changes to the liquid state. Warming of the liquid results.

Conduction is the transfer and distribution of heat energy from atom to atom within a substance.

Convection is the transfer of heat energy in a gas or liquid by movement of currents. The heat moves with the fluid.

Diffusion: The movement of a gas, liquid, or solid as a result of the random thermal motion of it atoms or molecules. For instance, a drop of food coloring in water will slowly spread throughout the water. Blood will diffuse through the ocean and attract sharks. Eek!

Energy is defined as the ability to do work. Imagine this: if you push or pull an object (like a car) and it moves, you have done work! If you push on a car and it doesn't move, you have done no work. (Even though you may be on the verge of a heart attack. It may not be fair, but it is true. ) The amount of energy used to move the car can be calculated with this equation: Work = force x distance.

Evaporation is when a liquid changes state to the gaseous state. This occurs at the surface of the liquid when random molecules escape from the surface of the liquid. As evaporation occurs, the liquid cools.

Force: Force is expressed in NEWTONs (N). A force of 1 newton will accelerate a MASS of 1 kilogram to a speed of 1 meter per second in 1 second. A small, 100-gram apple on a tree experiences a gravitational force of about 1 newton.

Heat: The energy that flows from one object to another by virtue of differences in temperature.
Suppose your hands are cold and you put them under your armpits to warm them up. The energy that flows from your warm pits to your cold hands is called "heat." Heat will raise the temperature of your hands. Heat is capable of being transmitted through solids by conduction, through fluids by convection, and through empty space by radiation. It is measured in calories or Joules. To heat a substance is to do a form of microscopic work because the added heat causes the individual molecules of the substance to move more rapidly about in all directions.

Internal Energy: It is the sum of kinetic and potential energies in an object.

Joule: If you were to push a book a distance of one meter with a force of one newton, you will have expended a joule of energy.

Kinetic energy is energy of motion. Remember roller coasters? A car that moves faster has more kinetic energy than a car that moves slower. Atoms have "Kinetic Energy" too because they move. The atoms in a hot object move faster than atoms in a cold object. The atoms in a hot object have more kinetic energy than the atoms in a cold object. Adding heat to a substance will make the atoms vibrate more and when heat leaves the substance; the atoms will vibrate less.

Power = Work/time

Potential energy is stored energy. Remember winding up your Souxie-Q's? The rubber band stored the potential energy. Potential energy is the energy of position or state.

Radiation: Electromagnetic waves that directly transport ENERGY through space. Sunlight is a form of radiation. The sun's energy is radiated through space to our planet. Radiation transfers heat at the speed of light without the aid of matter.

Regelation occurs when something melts under pressure and then refreezes when the pressure is removed. For instance, ice skates apply pressure to the ice rink and melt the ice. The water refreezes as soon as the skate removes the pressure.

R-Value: This measures the effectiveness of insulation. The higher the R-value of a material, the greater its insulating capability. (It is a measure of a material's resistance to heat flow in units of Fahrenheit degrees x hours x square feet per Btu.)

Specific Heat is the number of calories needed to raise 1 gram of a substance 1 degree Celsius.

Temperature is a measure of the average kinetic energy of the particles. Temperature is a measure of how hot or cold something is. Temperature is not the same thing as heat. Temperature can be measured in Celsius, Fahrenheit or in Kelvin.

Thermodynamics (thūrmo-di-na-miks) n.
1.Physics that deals with the relationships between heat and other forms of energy. (Dictionary.com)
2. Branch of science concerned with the nature of heat and its transformations to mechanical energy.
(Thermodynamics stems from the Greek words meaning "movement of heat.)


Law 1: Energy can neither be created nor be destroyed. It can change form and travel to other places, but it can always be accounted for. Heat added to a system (like a steam train) will increase the internal energy of the engine plus the opportunity to do some external work (Like move the piston and move the drive wheels). However, the energy output of the train cannot exceed the energy input.


Law 2: Heat will not flow spontaneously from a colder body to a hotter body. The law states that ENERGY FLOWs from a higher concentration to a lower concentration. It flows from hot to cold. Disorder tends to increase. Entropy tends to increase. Hamsters take over the world...(Just kidding about the hamsters.)

Work = Force x Distance. Work = Mass x Gravity x Distance. You can use this equation to calculate work done when you apply a force to an object and move it a certain distance. For example, if you applied 2 newtons of force to a chair and you moved it 5 meters; you will have done 10 Joules of work. Work is measured in newton-meters or Joules.

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