Kinetic vs. Potential Energy
The energy of motion. Anything moving (a rolling ball, a vibrating particle) has kinetic energy. Depends on mass and speed.
What is kinetic energy?
This method of transfer requires direct contact, and particle-to-particle collisions pass energy along; no matter moves, only energy.
What is conduction?
The amount of energy required to raise the temperature of 1g of a substance by 1 degree.
What is specific heat?
Furnace heats air; a blower pushes it through ducts to vents in each room. Most common in U.S. homes; ducts can also carry cooled air in summer.
What is a forced air system?
No energy or matter can cross the boundary — completely sealed off.
What is an isolated system?
Stored energy, ready to be used. Depends on position, shape, or arrangement (a stretched rubber band, water behind a dam, chemical bonds in food).
What is potential energy?
This type of heat transfer describes the movement of a fluid where heated fluid becomes less dense and rises; cooler, denser fluid sinks, forming a current.
What is convection?
Water is an example of a substance with a _____ specific heat, and aluminum is an example of something with a ________ specific heat.
What is high and low?
A boiler heats water (sometimes to steam) and pumps it through pipes to radiators — heat reaches the room by both convection and radiation.
What is a radiator or hydronic heating?
Energy and/or matter CAN cross the boundary. Almost every real-world system is non-isolated (e.g., a pot of soup losing heat and steam to the air).
What is a non-isolated system?
The TOTAL kinetic + potential energy of all the particles in an object.
What is thermal energy?
This type of heat transfer doesn't need a medium to travel through.
What is radiation?
How much energy is gained when 100g of water is heated 4 degrees? q=mCT (c=4.18)
What is 1672 J?
Electric current flows through a resistive element, converting electrical energy directly into thermal energy (baseboard heaters, electric furnaces, radiant floors).
What is electric resistance heating?
Energy transferred when a FORCE moves an object across a distance — not caused by temperature.
What is work?
The kinetic energy of a 148g baseball traveling at 31.3 m/s. (1/2mv2)
What is 7.25*104J?
Transfer heat quickly — usually metals (copper, aluminum, iron, silver) because of free-moving electrons.
What is a thermal conductor?
How much energy is lost when a 5.12g metal spoon with a specific heat of 0.541 J/gC cools by 3.00 degrees?
What is 8.31 J?
Uses building design ALONE (large south-facing windows, thermal mass like brick/stone/concrete) — no pumps, fans, or panels.
What is passive solar?
Energy transferred because of a TEMPERATURE DIFFERENCE — always moves warm → cool.
What is heat?
The kinetic energy of a 575,000 kg plane traveling at 250m/s.
What is 1.80*1013J?
Transfer heat slowly — wood, plastic, rubber, air/foam. Used to keep heat in or out on purpose.
The substance that would heat the fastest on a hot day:
water
sand
plastic spoon
What is sand?
Uses mechanical equipment — solar collectors/panels, pumps or fans to move and store the sun's energy.
What is active solar heating?
Columns of rising warm air, created when the sun heats the ground unevenly — a natural form of convection.
What are thermals?