Extra Credit Project

[JahJahwarrior]

This is an extra credit project for my math class. I don't even want to try.... If any of you all have any really great ideas on how to solve this (especially in a really creative way that still works out mathematically and logically) I'd love to hear them.


You are a CSI detective called to the UFO crash site in South Dakota. The single "mannged" craf crashed into a hill at 1,000 feet above sea level Upon investigation it was determined that the craft had burrowed into the hill to a depth of 1ft. Also determined was that the treajectory was exponential. The lone ET quickly succumbed to our hostile envireonment. Another casualty at the site was a brown cat. Cause of death was blunt force trauma to the head initially dteermined to be from a section of debris having the cat's blood on it. The batd's blood wasn't the only "bloodlike" fluid found on the debris however. The cat's liver temp. at time of discovery was 90 degrees F. One hour later that temp had dropped to 80 deg. F. The alien's temp. at time of disc. is 90 deg. F. The normal temp is known to be 110 deg. F. The heat diffusivity constant is 0.03. Ambient temp at the site is at a constant 70 deg. F.

1) how long in hours has the alien been dead
2) how long has the cat been dead.
3) how did the cat die
4) sketch a model of the situation
5) express in an equation the descent of the UFO
6) define any unfamiliar terms

 

[fairybasslet]

Yeah right. Call me when the movie comes out.

 

[ETnScuba]

Dead :kittykay: and a dead :icon28: ! I give up.

 

[PerfectD3]

Ummm before I help is there any change in ambient temperature due to time? Was there heat loss due to convection? If this is all you were given I will help as I can. For the alien I got 1.49 hrs before the time of discovery. The cat I will work on when I get home from work.

I used Newton's Law of Cooling.

EDIT: Change your temps to C and use values to 0.00

 

[JahJahwarrior]

As best as I can tell, the temperature of the air never changes, never changed before and might never change after kind of ilke florida's springs.

newton's law of cooling eh? I'll look into that. Eventually I have to do all the work myself

I can convert them to C for you if you want, but that will have to come later, now I need to leave to get to school.

 

[PerfectD3]

No I was informing YOU to change them to C before you worked that equation. I passed this on to one of the older engineer's (with a sense of humor) and this is his response....

This is unanswerable with any degree of accuracy based on the following factors.



1) Time of death estimations based on temperature is extremely inaccurate and based on a sigmoid curve (see diagram)





At least 5 temp/time observations need to be made to create this chart, based on variables of the individual cadaver. Differences in convection, radiation and evaporation changes based on several factors such as wet clothing, shock, hemorrhage, cardiac events prior to death (changes the initial temperature), agional breathing (such as an alien choking on a cat), fat tissue, muscle mass, wind speed, chill factor, ambient humidity, cadaver partial of full immersion, type of clothing (fur), etc. are all variables that must be taken into account, so a flat constant is too inaccurate.



2) “Exponential” trajectory does not provide enough information to plot the course of the ship. If by exponential, it is meant 8.91 meter/second/second fall from an unknown point to 1000’ above sea level than not enough information has been provided. If it is an exponential decent meaning linear distance versus vertical distance, we need several variables to determine the speed (coefficient of drag v mass, maximum speed based on wind resistance, cruising speed before decent, etc)



3) The depth of impact is a red herring as we are not given the CBR (California Bearing Ratio) or any other data about the soil strata. Were it 100’ deep solid bedrock, a 1’ crafter would indicate an enormous impact speed, but a 1’ crater is soft mud or peat assumes a soft landing.



Therefore any assumption is just that a pure assumption: I therefore assume

The alien abducted a common housecat for an intergalactic snack for his return voyage. Prior to leaving the planet, the greedy alien attempted to eat the cat whole and choked. This raised is body temperature as he hacked and snarfed to eject the cat from his respiratory system. During this time, the alien lost control of his spacecraft, which was traveling at a leisurely 12 MPH which lodged into the soft loam of a hillside. The crash did affect several of the ship’s systems, causing a coolant leak. Before passing our from the massive hemorrhaging the cat’s claws caused to his throat, the alien escaped from the vessel and tripped on the exit ramp. He landed across a tree trunk dislodged by the crash, which caused a “Heimlich” maneuver jettison the cat from his larynx in a shower of blood. The ejected cat was killed on impact and rolled into a pool of spilled coolant. The alien expired on the spot from massive shock-trauma. Then the ship exploded, but damage to the alien corpse was minimized by the fire-resistant spacesuit and the resulting fire was quenched by odd chemical process caused by lighting cat fur soaked in alien blood-vomit. Hey if you are going to force me to guess I might as well think big right? If you would like to hear the alternate vesion which includes the transporter error brough about by the arrival of the messiah and the Easter Bunny, I can give you that too.

 

[JahJahwarrior]

Do you or your engineer friend mind if I give him that, verbatim, with the addition of "working with a friend, the following problems were found:" ? That whole thing is freaking hilarious!



There is another problem which says there are 10 stacks of coins, 1 stack is fake. That stack is a different weight (it might say if they are heavier or not, I don't have this one in front of me) What is the minimum number of weighings needed to find the fake stack? I say 3: split the 10 into two groups of five, weigh them on one of those balance scales (this is assuming you have one, the problem doesn't say which type of scale). The one that is either heavier or lighter is the one with your counterfeit stack. Discard of the good group, then split the group of 5 into two groups of 2. Weigh those. If they balance, the counterfeit stack is the one not beign weighed. If they do not, take the stack that is either heavier or lighter, and balance those two against each other. The one that is either heavier or lighter will be your counterfeit stack. By pure luck, you could get it with one measure, but three measurings will make sure you get it.