Physics Ch 7 Flashcards
Energy
Ability to do work
Conservation of energy
Energy can neither be created nor destroyed
Work
Product of the component of the force in the direction of motion times the distance through which the force acts
Newton-meter
SI unit of energy & work; AKA joule or 1 kg m^2/s^2
Net work
Sum of all work done by external forces
Work-energy theorem
Net work on a system equals the change in the quantity 1/2 mv^2
Translational kinetic energy (KE)
Energy associated with translational motion
Gravitational potential energy (PEg)
Energy associated with the state of separation between 2 objects that attract each other by the gravitational force; energy stored in the gravitational field of Earth
Conservative force
Work force done by or against it depends only on the starting and ending points of a motion and not on the path taken
Conservative force
Work force done by or against it depends only on the starting and ending points of a motion and not on the path taken
Potential energy
Energy a system has due to position, shape, or configuration; stored energy, completely recoverable
Potential energy
Energy a system has due to position, shape, or configuration; stored energy, completely recoverable
Potential energy of a spring (PEs)
Work done on the spring & the energy stored in it as a result of stretching or compressing it a distance, x
Potential energy of a spring (PEs)
Work done on the spring & the energy stored in it as a result of stretching or compressing it a distance, x
Conservation of mechanical energy
Form of the work-energy theorem for conservative forces
Conservation of mechanical energy
Form of the work-energy theorem for conservative forces
Mechanical energy
Kinetic + potential energy of a system
Mechanical energy
Kinetic + potential energy of a system
Nonconservative force
Work depends on the path taken
Nonconservative force
Work depends on the path taken
Thermal energy
the energy within an object due to the random motion of its atoms and molecules that accounts for the object’s temperature
Thermal energy
the energy within an object due to the random motion of its atoms and molecules that accounts for the object’s temperature
Electrical energy
Energy carried by the flow of a charge
Electrical energy
Energy carried by the flow of a charge
Chemical energy
the energy in a substance stored in the bonds between atoms and molecules that can be released in a chemical reaction
Chemical energy
the energy in a substance stored in the bonds between atoms and molecules that can be released in a chemical reaction
Radiant energy
the energy carried by electromagnetic waves
Radiant energy
the energy carried by electromagnetic waves
Nuclear energy
energy released by changes within atomic nuclei, such as the fusion of two light nuclei or the fission of a heavy nucleus
Nuclear energy
energy released by changes within atomic nuclei, such as the fusion of two light nuclei or the fission of a heavy nucleus
Efficiency
a measure of the effectiveness of the input of energy to do work; useful energy or work divided by the total input of energy
Efficiency
a measure of the effectiveness of the input of energy to do work; useful energy or work divided by the total input of energy
Power
Rate at which work is done
Power
Rate at which work is done
Watt
SI unit for power
Watt
SI unit for power
Horsepower
746 w
Horsepower
746 w
Kilowatt hour
unit used primarily for electrical energy provided by electric utility companies
Kilowatt hour
unit used primarily for electrical energy provided by electric utility companies
Metabolic rate
The rate at which the body uses food energy to sustain life and to do different activities
Metabolic rate
The rate at which the body uses food energy to sustain life and to do different activities
Basal metabolic rate
total energy conversion rate of a person at rest
Basal metabolic rate
total energy conversion rate of a person at rest
Useful work
work done on the outside world; requires a force exerted through a distance
Useful work
work done on the outside world; requires a force exerted through a distance
Renewable forms of energy
Sources that can’t be used up
Renewable forms of energy
Sources that can’t be used up
Fossil fuels
Oil, natural gas, & coal
Fossil fuels
Oil, natural gas, & coal
