64 terms

# ICP Chapter 13/14: Energy

#### Terms in this set (...)

Work
Transfer of energy as the result of motion
Explain force and distance in work
Both have to be in the same direction
Equation for work
Force times distance
Units for work
N x m. Kg x m/s^2 x m. Kg x m^2/s^2. Joule
Work equation examples
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Power
How fast the work is done
Equation for power
Work/time
Units for power
J/s. Kg x m^2/s^2/s. Kg x m^2/s^3. Watt
American units for power
Ft lb/s. Horsepower
Conversion from ft-lb/s to watts to horsepower (hp)
550 ft lb/s = 746 w = 1 horsepower
Power equation examples
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Energy
Ability to do work. Ability to cause a change in itself or its environment
Five main types of energy
Mechanical. Thermal. Electromagnetic. Chemical. Nuclear
Mechanical energy
moving objects
Thermal energy
Heat, Temp, etc.
Electromagnetic energy
Chemical energy
Endothermic and exothermic reactions
Nuclear energy
radio activity, nuclear fusion, nuclear fission
What can the types of energy be divided into
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Kinetic energy
Energy due to the motion of an object
Equation for kinetic energy
KE=1/2mv^2
Units for kinetic energy
Kg x m^2/s^2 or joule
What happens to the kinetic energy of you double the mass
Ke is doubled
What happens to the kinetic energy if you double the velocity
Four times the ke
Potential energy
Energy due to the position or condition of an object
Gravitational potential enegy
Due to position
Calculation for gravitational potential enrgy
Pe=Weight x height. Pe=mass x g x height
Example of condition of potential energy
Rubber bands. Springs
Examples for equation of potential energy
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Law of conservation of energy
Energy cannot be created or destroyed. Can change forms. Total energy in the universe is constant
Describe energy of rock on top of hill
Top no ke all pe. Middle pe decreases because height decreases. Ke increases because speed increases. Bottom all ke
What would happen to a pendulum if there was no friction
It would go forever but in real life friction changed mechanical to thermal
Thermal energy
Total energy of the particles that make up a substance
What happens to the thermal energy when the mass is greater
More energy
Is the thermal energy related to the motion f the ovject
No
Temperature
Average kinetic energy of the particles in a substance
Does the number of particles affect the temperature
No
Explain thermometer
Liquid expands when heated. Length of column indicates temperature
Celsius to farenheit
Tf=9/5tc+32
Fahrenheit to Celsius
Tc=5/9(tf-32)
Kelvins to celsius
Tc=tk-273
Celsius to kelvins
Tk=tc+273
Si unit for temperature
Kelvin. No negative temperatures
Temperature conversion examples
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Heat
The transfer of energy from an object at a higher temperature to one at a lower temperature
Compare work and heat
Both a transfer of energy. Both measured in joules. Both not a property of a substance
Difference between work and heat
Work is energy transferred by mechanical means. Heat is energy transferred by thermal means
Si unit for heat and thermal energy.
Joule
Calorie
Amount of heat required to raise the temperature of one gram of water by one Celsius degree
calorie to kilocalorie to Calorie
1 kcal=1000 cal=1 Cal
calorie to joule
1 cal=4.19 J
BTU
British thermal unit. Amount of heat required to raise the temperature of one pound of water by one Fahrenheit degree
BTU to calorie
1 BTU=252 cal
List units for heat and thermal enetgy
Joule. calorie. Kilocalorie. Calorie. BTU
Specific heat (c)
Amount of energy needed to increase the temperature of one kilogram of s substance by one Celsius degree. Unique for every substance
Specific heat for water
4186 j/kg•C
How do you measure thermal energy
You cant. Can only calculate change in thermal energy
What is the change in thermal energy
Energy lost or gained
Equation for change in thermal energy
Q=mass x specific heat x change in temp
Units for change in thermal energy or q
Kg•j/kg•c • c=j
Examples for q equation
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Calorimeter
Instrument used to measure changes in thermal energy because it is designed so energy cannot escape or enter the system
Method of mixtures
When substances of different temperatures are combined They end up at the same temperature. Equilibrium
What is the perfect situation of method of mixtures
Amount of thermal energy lost(q)=amount of thermal energy gained(q)
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