Unit B Energy Flow in Technological Systems : Section 3.0 Flashcards

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1
Q

What is a system?

A

Objects or objects involved in energy transfers

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2
Q

What is an open system?

A

A system that exchanges both matter and energy with its surroundings. Eg. Earth

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3
Q

What is a closed system?

A

A system that cannot exchange matter but can exchange energy with its surroundings. Eg. A can of soup

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4
Q

What is an isolated system?

A

One that cannot exchange either matter or energy with its surroundings

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5
Q

What does work involve the movement of?

A

Matter from one location to another

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6
Q

What does heat involve the movement of?

A

Thermal energy from one location to another

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7
Q

What are the two ways a system can gain energy?

A
  • Heat can be added to the system from surroundings
  • Work can be done on a system from its surroundings
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8
Q

What is positive work?

A

Work done on a system by its surroundings, because the energy of the system increases

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9
Q

What are the 2 ways the energy of a system can decrease?

A
  • Heat can flow out of a system from its surroundings
  • Work can be done by system on its surroundings
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10
Q

What is negative work?

A

Work done by a system on its surroundings because the energy will decrease

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11
Q

What is the first law of thermodynamics?

A

The total energy, including heat, in a system and its surroundings remains constant

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12
Q

What will an ideal machine do?

A
  • All the input energy is converted into mechanical energy. without any energy loss
  • the amount of the mechanical energy produced by the machine should equal the amount of energy put into the machine
  • Operate indefinitely
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13
Q

What is the second law of thermodynamics?

A

Heat always flows naturally from a hotter object to a colder object, but never naturally from a cold object to a hot object

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14
Q

What is a heat engine?

A

A device that converts heat into mechanical energy. Only some of the heat can be converted into mechanical energy. The remaining is expelled as exhaust heat.

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15
Q

What are heat pumps?

A

Devices that use mechanical energy to transfer heat

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16
Q

How does a thermo-electric converter fan work?

A

One end of metal is placed in hot water and the other end is placed in cold water. As heat flows through the metal to the colder end the thermal energy is converted into electrical energy which the fan converts into mechanical energy

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17
Q

What are some of the simple machines?

A
  • Lever
  • Pulley
  • Wheel and Axel
  • Screw
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18
Q

What were the original sources of energy for machines? List four.

A
  • humans
  • animals
  • wind
  • water
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19
Q

What was the first machine to use “hidden energy”

A

Hero’s Steam engine

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20
Q

What was Hero’s Steam engine?

A

A novelty device that did nothing useful

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21
Q

What was one of the major problems with coal mines?

A

Pumping out water

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22
Q

What were the two ways that they pumped water out of coal mines? Then what did Savery invent?

A
  1. Archimedes screw
  2. Persian wheel with the reciprocating pump

Then Savery came up with the steam pump that forces water through pipes (by boiling water with the coal) and can lift water up 6 m.

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23
Q

What were the downsides to the Archimedes screw?

A

-The water was too heavy to lift

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24
Q

What was the downside to the reciprocating pump?

A
  • Atmospheric pressure can only push water up to height of 9m
  • It was limited in the height it could raise water
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25
Q

By who and when was the Gunpowder Engine made?

A
  • 1680
  • Christian Hagans (mathematician and physicist)

(gunpowder was invented by the Chinese way before this)

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26
Q

How did the Gunpowder Engine work?

A

-Christian Hagans used gasses generated by an explosion to drive a piston downwards into a cylinder

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27
Q

What were the drawbacks to Gunpowder Engines?

A
  • Hazards of explosions
  • No powerful internal mechanism to pull the pull the piston back up
  • Could not operate continuously
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28
Q

What were some scientific discoveries connected with a steam engine?

A
  • The power of vacuums
  • Water expands its volume 1300 times when heated to form steam
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29
Q

Who created the earlier heat/steam engine and when was it created?

A
  • Denis Papin
  • 1690
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30
Q

How does a Heat/Steam engine work?

A
  • Water is heated so it turns to gas, the gas pushes the piston up
  • Water is then pumped on the outside to condense the steam
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31
Q

What were the drawbacks to Heat/Steam engines?

A

-Manufactures had difficulty producing big enough drums where water could be heated

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32
Q

Who created the Savery engine and around when was the Savery engine created?

A
  • Thomas Savery, English military engineer
  • 1698
33
Q

How did the Savery engine work?

A

Used pressurized steam to force water through pipes

It was a pump to pump water higher in order to clear the coal mines of water. It used heat to make this happen.

34
Q

What were the drawbacks to the Savery engine?

A

The pump could not lift water higher than 6 meters

35
Q

Who created the Newcomen engine?

A

Thomas Newcomen 1712

36
Q

How did the Newcomen engine work?

A

A water pump:

A boiler produced steam that forced a piston up a cylinder. Cold water was then sprayed on the outside to condense the water and move the piston back down. The piston was connected to a rod which pumped water out

37
Q

What were the drawbacks of the Newcomen Engine?

A

-The cycle of heating and cooling the cylinder was inefficient since the heating and cooling occurred in the same place (this quick shift between hot and cold damaged the equipment faster)
- the engine required tremendous amount of heat to function

38
Q

Who created the Watt engine? Around when was it created?

A

James Watt in 1763

39
Q

Explain the Watt engine

A

Watt created an engine that used steam but instead of using the same boiler to heat and cool steam a separate boiler was used to condense steam. This made it 3 times more efficient

40
Q

What were the drawbacks to the watt engine?

A
  • Very large
  • Needed big boilers (separate boilers were what was new here but they still needed to be huge)
  • Hot, dirty, and very inefficient compared to our engines today, but still an improvement over having the hearing and cooling in the same boiler for efficiency
41
Q

How did the internal combustion engine work?

A

Coal was ignited by an electrical spark. The coal releases energy under pressure. It was done under pressure because it produces more force

42
Q

What were the drawbacks to internal combustion engines?

A
  • Very inefficient and could not produce sufficient force
  • Used coal as fuel and coal doesn’t burn very hot
43
Q

What is the purpose of a machine?

A

To convert the initial energy added to it into types of energy needed to get work done

44
Q

What is wasted energy in a machine?

A

The energy that is not used to get work done

45
Q

What is energy input?

A

The initial energy source

46
Q

What is useful energy output?

A

The desired energy needed to do the work

47
Q

What is useful work output?

A

The work the machine is supposed to do

48
Q

In a lightbulb what is the useful energy and what is the wasted energy?

A

The useful energy is the light output and the wasted energy is the heat output

49
Q

How do systems with moving parts lose energy?

A

Through heat due to friction

50
Q

Where is some heat always lost to in a thermal energy transfer?

A

To the surrounding

51
Q

What is efficiency of a machine?

A

A measurement of how effectively a machine converts energy input into useful energy output

52
Q

What is the formula for efficiency?

A

Efficiency = useful work output/total work input

53
Q

What is the most reliable source of energy?

A

The sun

54
Q

What are the 2 categories for primary energy sources?

A

Solar and Non-Solar energy sources

55
Q

What are the 5 types of solar energy sources?

A
  • Solar Radiation
  • Wind Energy
  • Water Energy
  • Biomass
  • Fossil fuels
56
Q

What are solar energy sources?

A

Energy sources that are derived either directly or indirectly from the energy of the sun

57
Q

What is solar radiation energy?

A
  • The radiant energy emitted from the sun by the hydrogen-hydrogen nuclear fusion
  • Travels through space as electromagnetic radiation
  • Captured by plants, solar panels, solar cells, etcetera
58
Q

What causes wind? What is wind energy?

A
  • The result of heating of the earth’s surface by the sun
  • Heating causes currents of air which is wind since land is heated differently than water due to the different specific heat capacities
  • The energy in the movements of the air is used to turn turbines
59
Q

What is water energy?

A
  • Results when the surface of water is heated by the sun
  • this warming is the cause of the hydrolic cycle
  • Heating by the sun causes evaporation of water into the atmosphere where it condenses into rain.
  • Falling rain creates kinetic energy which can be used to power other things

So water energy is really gravitational potential energy since when it falls it can cause things to move. This is hydro power.

60
Q

What is biomass?

A
  • Any form of organic matter
  • They store energy from the sun through photosynthesis
61
Q

What are fossil fuels?

A
  • Oil, natural gas, coal
  • Fossil fuels were formed by plants and animals years ago
62
Q

What are non-solar energy sources?

A

Energy sources that have no relationship to the sun

63
Q

What are the three types of non-solar energy sources?

A
  • Nuclear-Energy
  • Geothermal energy
  • Tidal energy
64
Q

What is Nuclear energy?

A

-The energy obtained from a conversion of mass to energy in nuclear reactions

For example, uranium loses protons and in the process releases energy.

65
Q

What is Geothermal energy?

A
  • Energy from the Earth’s interior
  • Geothermal plants use superheated water to turn turbines
66
Q

What is tidal energy?

A
  • The movement of ocean water creating tides
  • The kinetic energy can be converted to other forms of energy
  • caused by the gravitational attraction if the moon
67
Q

What are renewable energy sources?

A

Energy sources that are continually and indefinitely available

68
Q

What are the types of renewable energy sources?

A
  • Solar
  • Wind
  • Water
  • Geothermal
  • Tidal
  • Biomass
69
Q

What are non-renewable sources of energy?

A

Sources of energy that are limited and irreplaceable (Nuclear and Fossil Fuels)

70
Q

What is the most important energy type to generate for the population?

A

Electrical energy

This is the energy type that is used the most often and thus has more importance to generate.

71
Q

What percent of the energy consumed is electrical?

A

40%

72
Q

What are the 3 factors that increase demand for energy supplies?

A
  • Increasing energy consumed per person
  • World population growing exponentially
  • The use of non-renewable energy sources that are limited (scarcity) instead of something more limitless
73
Q

How does burning of fossil fuels affect the world?

A
  • Emissions create greenhouse gasses
  • Greenhouse gasses contribute to climate change and acid rain
74
Q

What would happen if everybody cut their consumption of fossil fuels by 25 percent?

A

It would extend reserves by 25%

75
Q

What are the largest consumers of energy in industrialized countries?

A

Bussiness and Industry

76
Q

What is Congregation?

A

Using the waste energy from one process to power a second process

77
Q

What does sustainable mean?

A

Any process that will not compromise the survival of living things or future generations while still providing current energy for needs

78
Q

What is sustainable development?

A

Economic development that meets current needs without compromising the ability for future generations to meet their needs