Chapter 5-Energy and Thermodynamics Flashcards
Work
The process of transferring energy
Energy
The ability to produce a change/the ability to do work
Power
the rate at which work is done/the rate which energy is transferred
What Situation is work done in?
When a FORCE is applied and the object MOVES in response to the force
Postive work
Work is done by a force in the direction of the objects displacement
Negative work
Work is done by a force that acts in the opposite direction of the objects displacement
Kinetic Energy
The energy of motion/the energy that an object has because its moving
Net Work Thm
Net work done on an object equals its change in kinetic energy. Wnet=ΔKE
Potential Energy
energy stored as a result of position of an object or the configuration of atoms in a substance
Gravitational PE
Energy that is stored due to its place on a gravitational field PEg=MGH
Elastic PE
Energy that is stored in sings or there springy things PEe=1/2KX^2
Mechanical Energy
Energy involving forces and motion (Kinetic, PEg, PEe)
Law of Conservation of Mechanical Energy
The total energy in a closed system stays constant. This is the sum of all energy is constant
Closed System
A system in no external forces acting on the system and no changes in the mass of the system
How is mechanical energy lost in a rollercoaster
It is converted into unusable energy like heat or bending the material
Temperature
Temperature is a measure of the average kinetic energy of particles in a substance
Internal Energy
Internal energy is the total energy related to motion of particles in a substance, including kinetic, potential, and rotational energies
Thermal Equilibrium
When two occurs when two objects are in thermal contact with each other and are at the same temperature
Heat
Heat is the energy that flows between objects with different temperatures
Specific Heat Capacity
The amount of energy needed to raise one unit of mass of a substance by one unit of temperature. (Joules per kg or C)
Phase Change
The transition between states of matter, such as solid to liquid or liquid to gas
Heat of Fusion
(Latent Heat) Heat of Fusion is the amount of energy required to melt a unit of mass of a substance at its melting point
Heat of Vaporization
(Latent) Heat of Vaporization is the amount of energy required to vaporize a unit of mass of a substance at is boiling point
Thermal Expansion
The change in the size of a substance due to the change of temperature
Conduction
the heat transfer due to particles in direct contact with each other
Convection
The heat transfer through the motion fluids
Radiation
Radiation is the transfer of heat through electromagnetic waves
Isovolumetric Process
A thermodynamic process that takes place at a constant volume so that no work is done
Isothermal Process
A thermodynamic process that takes place at constant temperature
Cyclic Process
A thermodynamic process in which a system returns to the same condition under which it started
Adiabatic process
A thermodynamic process during which no energy is transferred to or from the system as heat
Heat Engine
A heat engine is a device that uses heat to do mechanical work
Efficiency
Efficiency is the ratio of useful work produced by a system such as a heat engine to the energy into the system
Entropy
Entropy is a measure of disorder or randomness or a system
Kinetic Theory of Matter
All matter is made up of particles that are constant in motion. This motion is responsible for the thermal properties of all substance
Do objects at the same temperature have the same internal energy?
No, unless they have the same mass and specific heat capacity
Why does a thermometer measure its own temperature?
The reading depends only on the temperature of the liquid inside. An accurate measurement can only be made after the thermometer has reached thermal equilibrium with the substance being measured
Body radiation vs Light Radiation
Body: longer wavelengths, infrared light
Light: hotter, shower wavelengths, visible light
Why does metal feel colder than wood at the same temperature?
Metal is a better conducted than wood so your heat transfers from your hand faster to the metal
First law of thermodynamics
The change of internal energy of a system is equal to the added energy minus the work done by the system
Second Law of Thermodynamics
NO cyclic process that converts heat entirely to work is possible. This means that any engine must expel heat from which no work is created.
