MRIs useRadio wavesUltrasound imaging usesGamma rays
Ultraviolet rays
X-rays
Infrared radiation
NONE OF THE ABOVE (choose this)Without the greenhouse effect, the earth's average temperature would bewell below freezingCompared to 200 years ago, earth's current average temperature isA few degrees warmerThe strongest direct evidence for global warming isAn increase in earth's average global temperatureThe last time earth's atmosphere had CO2 levels similar to today's level was aboutProbably more than 20 million years agoIn the past 150 years, temperatures have increased the most inin the Arctic region (near the north pole)During the last half century, which of the following changes have we seen in hurricanes? Choose all that applyAn increase in the average latitude (farther north)
A likely increase in the accumulated energy indexWhich of the following are consequence of the thawing of the Arctic permafrost? Choose all that applyRelease of dormant microbes
Release of dormant pathogens
Release of CO2 and Methane
Crumbling of infrastructure
ALL ARE CORRECTThe melting of the arctic sea ice due to global warming isA positive feedback, leading to even more warmingIce loss in Antartica is occurring primarilyIn west AntarticaWhat fraction of anthropogenic CO2 in the atmosphere (i.e, that due to human emissions) is being absorbed by the oceans?about 30%As our demand for oil continues, we must rely on oil reserves that (Choose all that apply)Are more expensive to extract
require "dirtier" extraction techniques
require more refining
ALL ARE CORRECTThe main goal of the Paris Accord of 2015 is to keep global warming under 2C in order to achieve this we mustUse only about a third of our fossil fuel reservesWhat is energy? Choose all that applyThe ability to do work
The ability to exert a force in a way that causes motionA moving object hasKinetic energyWhich of the following are units of energy? Choose all that applyCalorie
Joule
Kilowatt hourOf the economic sectors below, which TWO contribute the most to greenhouse gas emissions?Transportation
Electricity generationWhat is the largest source of electric power generation in the United States?Natural gasWhat is the largest source of renewable electric power generation in the United States?WindPower isThe rate at which work is doneIn terms of deaths per trillion kWh which method of generating electricity is most deadlyCoalTrue or false Hydrogen fuel cell cars have zero net greenhouse gas emissionsNo correct answer listedWhat is meant by the Levelized Cost of ElectricityIt is the cost per kWh of electricity determined by total lifetime cost of a power plant divided by the energy the plant producesIn the last 20 years, the largest decrease in the Levelized Cost of Electricity has been forUtility scale solarA failure of an O-ring caused the space shuttle Challenger to explode. Why did the O-ring fail?Cold weather caused it to lose it's resiliency, and then it failed to seal properlyWhen heated most thingsExpandWater is different than most things because
Choose all that applyIt usually contracts when cooled, but it expands if it is close to freezing
It expands when it freezesWhich of the following are examples of using thermal changes to our benefit (rather than accomodating undesirable consequences of thermal changes)? Choose all that applyTNT
Airbags
Molding material in manufacturingSound in a gas travels faster than the temperature increases. Why?The molecules move, on average, faster at higher temperaturesConduction is a means of transferring heat throughContactLava lamps are a fun illustration of, mainly,ConvectionMountain ranges are a consequence ofConvectionThe rotation in hurricanes is a consequence ofThe coriolis effectA heat engine such as a power plant or gasoline car is most efficient whenthe temp ratio between the cold and the hot sides is the smallestA chemical element is defined byThe number of protonsIn order to be stable, a large nucleus needsMore neutrons than protonsAfter two half-lives of time have passed, what fraction of a radioactive sample will remain?1/4An alpha particle isA helium nucleusA beta particle isAn electronIf a nucleus emits a beta particle, what happens to the remaining nucleus?It becomes a different chemical element, having one more proton than before the emissionExposure (to radiation) refers toThe amount of radiation traveling through the airWhat is a typical dose equivalent of radiation that a person receives each year?About 100 remWhich type of radiation is most dangerous if the source is external to your body?GammaWhat is the threshold dose equivalent that will cause radiation illness?100 remWhat is a "cancer dose" of radiation?2500 remFission isthe breakup of a large nucleus into two smaller nucleiExponential growthStarts off slowly, but gets faster and faster over timeSpontaneous fissionis very rareA fissionable nucleusbreaks up into two smaller nuclei after absorbing a neutronA fissile nucleusPossibly: is capable of sustaining a chain reaction of fissions
BUT: No correct answer listedWhich of the following are potential fuels for nuclear reactors? Choose all that applyUranium 233
Uranium 235
Plutonium 239What is the purpose of a moderator in a nuclear reactorit slows down the neutrons that are emitted by fission eventsWhat is the purpose of control rods in a nuclear reactor?they absorb neutrons and is used to increase or decrease the rate of the nuclear reactionA plutonium reactor
Choose all that applyCreates more fuel as it operates
Produces a smaller volume of waste than a uranium reactorThe worst nuclear accident to date wasIn Chernobyl, Ukraine (USSR)The fission products that are in nuclear waste that are most problematic arethose with intermediate half-lives (5-100 years)How long does it take before the radioactivity in reactor waste has decreased to about 100 times greater than that of the original uranium ore?A few hundred yearsEnrichment of nuclear fuel refers toincreasing the proportion of U235 present in Uranium fuelWhat are the major impediments to building a plutonium bomb? Choose all that applyObtaining plutonium
Designing the bomb to prevent premature explosions
triggering the explosion
BUT NO CORRECT ANSWER LISTED
