CHE FINAL
Convert the temperature 9 oF to oC. Do not include units in your answer.
-12.8
If I wanted to express the force 10,000 N in a more convenient form, I could use the prefix notation in the SI system. Which of the following would be correct?
10 kN
A net force of 30 newtons is applied to a block of mass 10 kg, which causes that block to accelerate. The force that must be applied to a block of mass 5 kg to give it the same acceleration is ________ N.
15
If the annual growth rate of a population is 9.8 %, then in approximately how many years will it take for the population to increase by a factor of 8?
22.24 or 21.4
How many significant figures are in the following value: 3020.0 g
5
A common unit for density (how much mass there is in a particular volume) is kg/m3 . Please convert 5,841 kg/m3 into g/cm3 , which is another common form. Do not include the unit label in your answer.
5.84
Which of the following is the correct scientific way to express 7,256,000 W in scientific notation?
7.256 x 106 W
A major difference between alternating current (AC) electricity and direct current (DC) electricity is that __________. resistance in an AC circuit is continuously changing and is constant in a DC circuit Ohm's law holds for DC but not for AC AC voltage is easily changed using a transformer DC voltage is easily changed using a transformer
AC voltage is easily changed using a transformer
An electric transformer that steps up the voltage by a factor of 2 (e.g. increases the voltage from 120 V to 240V) does what to the current? Decreases current by factor of 4 Decreases current by factor of 2 Increases current by factor of 2 Increases current by factor of 4 Does not impact the current
Decreases current by factor of 2
Which of the following statements is the most correct?
Energy can be neither created nor destroyed.
Ohm's law provides a relationship between voltage (V), current (I) and resistance (R) in an electrical circuit. Which of the following equations is not a valid form of Ohm's law? Check all that apply. I = V/R I = R/V R = V/I I = VR R = I/V V = IR
I = R/V I = VR R = I/V
Methane is considered to be a major greenhouse gas (GHG) because: It is a strong thermal radiation absorber It is emitted in greater quantities than other GHGs Its concentration in the atmosphere is higher than other GHGs It is emitted in lesser quantities than other GHGs
It is a strong thermal radiation absorber
Several gases in our atmosphere contribute to the "greenhouse effect" on earth. Their contribution to the greenhouse effect varies based on which of the following characteristics? Check all that apply. Ability to form particles that reflect sunlight How well the gas destroys ozone in the stratosphere Ability to reflect visible and ultra-violet radiation Lifetime in the atmosphere Ability to absorb infrared radiation
Lifetime in the atmosphere Ability to absorb infrared radiation
Heat is _______________. a property of an object. the specific heat of an object. a measure of the average kinetic energy of molecules in an object. the energy transferred between bodies due to a temperature difference.
NOT: a measure of the average kinetic energy of molecules in an object
Which of the following devices does not use a heat engine? Diesel truck Jet airplane Electric car Conventional car Diesel locomotive
NOT: diesel truck
Energy from the sun is the source for which of the following? Check all that apply. Photovoltaic energy Hydroelectric energy Wind power Tidal energy Georthermal energy Nuclear energy
Photovoltaic energy Hydroelectric energy Wind power
Solar power towers create high temperature fluid for steam generation by ________. Redirecting sunlight from a large area to a central receiver by reflecting light with mirrors Redirecting sunlight to an absorber tube carrying fluid down the center of a reflecting trough. Collecting sunlight with photovoltaic cells and using the electricity generated to heat the fluid. Collecting sunlight in a trombe wall with internal pipes to heat the fluid.
Redirecting sunlight from a large area to a central receiver by reflecting light with mirrors
Which of the following are attributes of a passive heating solar system? Click all that apply. Uses a fan or pump to create flow of a fluid Relies on fluid density differences created by heating for flow Relies on photovoltaic cells for electric heating Relies on mirrors to direct solar energy to a receiver for power production
Relies on fluid density differences created by heating for flow
Which event most accurately describes the conversion of radiant energy to electrical energy?
The conversion of sunlight in a photovoltaic cell.
You are choosing an extension cord to plug in a portable electric heater. Which of the following would result in using a wire with the lowest resistance, and therefore the lowest loss of power in the wire? Choose all that apply. The longest cord The cord using wire with the highest conductivity The cord with the largest diameter wire The shortest cord The cord with the smallest diameter wire The cord using wire with the lowest conductivity
The cord using wire with the highest conductivity The cord with the largest diameter wire The shortest cord
Which of the following best describes "voltage" in the context of electricity? The driving force for electrical flow. The parameter measured in units of "amps". The material property that inhibits electricity flow in a wire. The movement of electrons. The parameter measured in units of "ohms".
The driving force for electrical flow.
Why does a solar power plant need to cover a large land area, on the order of several square miles? The intensity of solar radiation is relatively low and must be concentrated. The intensity of solar radiation is relatively high and must be concentrated. Heliostats must be placed far from the receiver in order to properly reflect sunlight. They are mostly in the desert where the land is cheap.
The intensity of solar radiation is relatively low and must be concentrated.
Which of the following best demonstrates a source of potential energy?
The water stored behind a dam
The combination of primary, secondary and enhanced oil recovery techniques can result in the extraction of how much oil originally present in an oil field? Up to 30-35% Up to 45-50% Up to 5-15% Up to 90%
Up to 45-50%
Electricity can be described as _______. the flow of protons the best way to transport energy over very large distances a convenient energy source a flexible way to use and transport energy a method to deliver energy at 100% efficiency
a flexible way to use and transport energy
Passive cooling of a building is done by ___________. a vertical thermal mass creates a flow of hot air, drawing cooler air into the building a vertical thermal mass cools the air in the building an air conditioner powered by solar panels a vertical thermal mass which radiates heat out of the building
a vertical thermal mass creates a flow of hot air, drawing cooler air into the building
A major advantage of a "smart" grid over today's electrical grid is... Connects power plants via high voltage transmission lines for redundancy allows increased use of renewable technologies Uses high voltage transformers to transmit power long distances Provides backup power in the form of additional power plants
allows increased use of renewable technologies
Which of the following types of coal is likely to have the highest carbon content? Subbitumenous Bitumenous Anthracite Lignite
anthracite
If a constant non-zero force is applied to an object, its acceleration will certainly ______.
be constant
The bulk of the heat released from burning natural gas (CH4) comes from ___________. combustion of hydrogen combustion of water vapor combustion of carbon dioxide combustion of carbon
combustion of hydrogen
Select the statement which most correctly completes the sentence. Your feet feel cooler on a tile floor than on a rug because the tile ... is a better insulator than the rug. has less internal energy than rug for the same mass. is usually cooler than the rug. conducts heat better than the rug. all of these.
conducts heat better than the rug
Inverters in rooftop solar electric systems are needed to ____________. convert DC power from the solar panels to AC convert AC power from the solar panels to DC step up low voltage from solar panels to house voltage convert single phase AC from the solar panels to three phase AC measure the energy exported from the solar panels to the grid
convert DC power from the solar panels to AC
Solar energy is quite compatible for a major part of the United States because our major energy needs are for _________ energy. thermal electrical kinetic potential mechanical
electrical
Radiant (light) energy can be described as:
electromagnetic radiation
Nuclear energy can be described as:
energy found within atomic nuclei
According to the Law of Conservation of Mass, matter cannot be created nor can it be destroyed. Conversely, the Law of Conservation of Energy states that energy can be created, but cannot be destroyed.
false
T/F: The efficiency of a multi-step process is always greater than the efficiency of its least efficient component.
false
True or False: The wavelength of low-energy light is shorter than it is for high-energy light.
false
When a pocket of fluid is heated, typically it will expand resulting in a decrease in density. Under this condition, the warm pocket of fluid is likely to ___________ if the surrounding fluid is at a lower temperature.
float
The balancing authorities controlling the electric grid ______________. increase and decrease power plant output to match production with consumption control electricity demand so that it matches production operate power plants at full capacity to ensure electricity demand is met control power plants to even out electricity production over a day
increase and decrease power plant output to match production with consumption
Carbon monoxide is an important pollutant from combustion because ___________. it combines with VOCs and light to produce photochemical smog it results in ozone destruction in the stratosphere it binds with hemoglobin in the blood to prevent the uptake of oxygen it deposits in the lungs and causes respiratory disease
it binds with hemoglobin in the blood to prevent the uptake of oxygen
The effciency of a light bulb is the ratio of the
light output to the electrical energy input
Which fossil fuel is used to generate the most electricity in the United States today? Tar Sands Oil Coal Natural Gas Petroleum
natural gas
The first law of thermodynamics states that energy can't be created or destroyed, but can change forms. The second law says which of the following when applied to energy conversion devices? Energy conversion from one form to another can be done without loss It is impossible to convert all of the heat energy in a system into useful work It is impossible to convert heat energy into work It is impossible to convert energy from one form to another It is possible to convert all of the heat energy to useful work
not: it is possible to convert all of the heat energy to useful work
According to over 200 US and international scientific organizations climate change is ..... occurring with natural processes as the primary driver. following the natural variations observed over the last 800,000 years. occurring and due to increased solar activity. occurring and has been caused by human action.
occurring and has been caused by human action.
Which of the following is not a base unit in the SI system? pound meter ampere second kelvin
pound
Which of the following environmental concerns is notassociated with hydraulic fracturing, or fracking? (check allthat apply) removal of mountain tops to extract coal emissions of methane and volatile organic compounds (VOCs) into the air use of large amounts of fresh water contamination of groundwater emission of particulate matter into the air
removal of mountain tops to extract coal emission of particulate matter into the air
Into which broad category of energy resources would solar and wind fall?
renewable
Solar photovoltaic panels use ____________ to collect solar energy and convert it to electricity. semiconductor materials transformers inverters heliostats mirrors
semiconductor materials
The purpose of fractional distillation of crude oil is to ...... separate components in the oil by their viscosity separate components in the oil by differences in their boiling points separate components in the oil by their sulfur content separate components in the oil by their carbon content
separate components in the oil by differences in their boiling points
Grid connected solar photovoltaic (PV) systems present challenges to electric grid operators because __________. the supply of electricity from solar systems is highly variable voltage from solar systems is not high enough for grid operations the frequency of AC from solar systems is difficult to control the current from solar systems is too low for grid operations
the supply of electricity from solar systems is highly variable
The electric grid consists of many interconnected parts which create a complex network. Which of the following parts is where electricity is delivered over long distances? Transmission Network Generation Points End Users Distribution Network
transmission network
Oil is mainly used for: Chemical Production Transportation Steel Production Home Heating Electric Power Generation
transportation
T/F: The wavelength will be longer for low-energy light than it would be for high-energy light.
true
True or False: The quantity of primary pollutants emitted each year in the US has consistently dropped since the Clean Air Act was passed in 1970.
true
Which of the following are units of power? Check all that apply. Watt Horsepower kilowatt hour kilowatt Joule Calorie
watt, horsepower, kilowatt
The major renewable energy source of electricity in the US is _________________. Geothermal energy Natural gas from fracking Solar Panels Wind turbines Hydroelectric dams
wind turbines
The net force required to move a body at a constant velocity in outer space (not on the planet) is ________.
zero
