part b please www.webassign.net web Student Assignment Responses lastdep 1630015

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part b please

www.webassign.net web Student Assignment Responses lastdep 16300155 Question Total 2/3-2/3 (66.7%) Points ent Submission assignment, you submit answers by question parts. The number of submissions remaini ent Scoring t submission is used for your score on parts. The nutmber of submissions remaining for each question part only changes if you submit or change the answer 2/3 points l Previous Answers NoonburgDMEQ1 2.1 022. (Newton's Law of Cooling) Disclaimer: The following problem is known not to be a very good physical example of Newton's Law of Cooling, since the thermal conductivity of a corpse is hard to measure; in spite of this, body temperature is often used to estimate time of death. At 7 AM one morning detectives find a murder victim in a closed meat locker. The temperature of the victim measures 900. Assume the meat locker is always kept at 40°, and at the time of death the victim's temperature was 98.6°. When the body is finally removed at 8 AM, its temperature is 880 When did the murder occur? (Round your answer to the nearest minute.) 3 (a) 07 am was known only to be between 98.20 and 101.4°2 (Round your answer to two decimal places.) (b) How big an error in the time of death would result if the live body temperature 03 hrs Submit Assignment Save Assignment Progress Home My Assignments Extension Requesf

Explanation / Answer

(b)

From part (a) , time of death for live body temperature 98.6° = 3:07 Am

Now if we given range only 98.2° - 101.4°

Assuming live body temperature as 100°F

By newton's law of cooling

T = (To-Ta)ekT+Ta

TO= 90°F, Ta= 40°F

After one hour , t= 1

T= 88°F

We have to find physical constant (k) as :

88= (90-40)×ek(1)+40

k= -0.041

Solving for time of death :

Ta= 40°F , T0= 100°F , T = 90°F

T= (To-Ta)×ekt+Ta

90= (100-40)×e-0.041t+40

e-0.041t= 0.833

-0.041t = ln(0.833)

t = 4.45 h

t~ 4 hours + 0.45 hours

~ 4 hours + 27 minutes

Time of death = 7 AM- 4hours 27 minutes = 2 AM33 minutes = 2: 33 AM

The error percentage can be find out as :

(4.27-3.53)/3.53 ×100 ~ 21%

Also depend on person , who choose body temp between 98.2 - 101.4 °F

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