Geography 1400F/G Chapter 4: Chapter Four Summary and Definitions Human geography

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22 Jan 2012

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Chapter four: population world patterns and regional trends: Birth, death, fertility, and growth rates are important in understanding the numbers, composition, distribution, and spatial trends of population. Control of population numbers historically was accomplished through a demographic transition first experienced in european societies that adjusted their fertility rates downward as death rates fell and life expectancies increased. The introduction of advanced technologies of preventative and curative medicine, pesticides, and famine relief have reduced mortality rates in developing countries without until recently always a compensating reduction in birth rates. Recent fertility declines in many developing regions suggest the demographic transition is no longer limited to the advanced industrial countries and promise world population stability earlier and at the lower numbers than envisioned just a few years ago. The demographic future for the next fifty years is as follows: the population will be 2-4 billion people bigger by. 2050 and nearly all of that growth will be in less developed countries.

A right triangle has legs ofknown lengths 2L and h. Find thelength of the line segment x whichis parallel to side h. Explainyour reasoning. Image in weblinkbelow:

http://paer.rutgers.edu/194/Downloads/194LAB07.pdfRY4bB71082bfFuqzISDrWGDOWfNgGl208qJNQTAhpzWjb_ahDlhGHPLz19S1Eq95&q=cache%3AnpyQu9LlzykJ%3Apaer.rutgers.edu%2F194%2FDownloads%2F194LAB07.pdf%20this%20geometry%20task%20may%20be%20helpful%20for%20devising%20a%20mathematical%20procedure%20for%20the%20next%20lab.%20A%20right%20triangle&docid=5c8a26db354186a31ce6383

POSTSCRIPT: EFFECTS OFASSUMPTIONS

The marbled murrelet is asmall bird that lives in the PacificNorthwest where old-growthforests are close to the sea. It nests inthe forests and feedsoffshore. It is now highly endangeredthroughout its range, whichextends from Northern California toAlaska.

These birds are extremelyvulnerable to loss of their habitat,because they nest exclusivelyin the same old-growth coniferoustrees that are prime targets forlogging. Considerable efforts havebeen made to protect the speciesby restricting timber operations inthe areas in which they areknown to nest. Scientists predicted thatthe population should growback. However until recently naturalistswere puzzledand

dismayed because thepopulation of marbled murrelets did notseem to be recovering oreven stabilizing.

A recent study suggests thereason why this testing experimentin conservation did not confirmthe prediction. The scientistsoverlooked an important assumption:murrelets can also be threatenedby man's activity at sea.Overfishing has severely reduced thepopulation of small,energy-rich fish that murrelets rely upon formost of theircalories.

Climate change of uncertainorigin may have also disrupted thefood chain, and El Nino currentsmay have changed the distributionof the phytoplankton that formsthe base of all marine life.

Further efforts to preservethe marbled murrelet must be basedon accurate assumptions aboutthe origin of their difficulties.

Could naturalists have betterconsidered their originalassumptions years ago? What would yousay?

It is currently popular for automobiles to use 10% ethanol / 90%gasoline mixtures (âgasoholâ) as fuel. According to popularconsensus the main benefit of gasohol use is that it âreduces ourdependence upon foreign oil.â We test this assertion by making someelementary calculations. Our analysis will unrealistically ignoreengine maintenance issues associated with older automobiles (suchas gasket and seal hardening), added fuel consumption necessary toproduce grain used as a feedstock in ethanol production,incremental food price increases associated with a reduction ingrain stocks, and many other effects. Gasohol use typically reducesaverage fuel economy by approximately 15% and effectively leavesfuel prices unchanged. This article further debates the wisdom ofethanol use and may be of interest outside the problems:
http://harvardmagazine.com/2006/11/the-ethanol-illusion.html
These concerns and problems have been strongly influenced byconversations with Dr. H.J. Harmon, of the OSU physicsdepartment.

2. Consider a 14.2 mpg 1991 Ford F150 driven 761 miles. Calculatethe pure gasoline consumption of this truck when: a) usinggasoline, and b) when using gasohol (with its attendant economyreduction). Determine the total CO2 emissions for each fuelassuming all fuels produce 20 lbs of CO2 per gallon. Comment uponthe wisdom of using gasohol versus pure gasoline in this vehicle.

Geography 1400F/G Chapter 4: Chapter Four Summary and Definitions Human geography

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