Mathematics, 16.07.2019 07:00, anthonybowie99

Abody was found at 10 a. m. in a warehouse where the temperature was 40of. the medical examiner found the temperature of the body to be 80of. what was the approximate time of death? use newton's law of cooling, with k = 0.1947.

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answered: KitKat22Rose9

The approximate time of death is 8 a.m.

Given that,

A body was found at 10 a.m. in a warehouse where the temperature was 40oF.

The medical examiner found the temperature of the body to be 80oF.

We have to determine,

What was the approximate time of death?

According to the question

The time of the death is determined by using Newton's law of cooling following all the steps given below.

$\rm T(t)= T_A+(T_o-T_A).e^{-kt}$

Where the value $\rm T_A$ is 40oF and $\rm T(t)$ is 60oF.

Substitute all the values in the formula.

$\rm T(t)= T_A+(T_o-T_A).e^{-kt}\\\\80=40+(98.6-40)e^{-0.1947\times t}\\\\80-40= 58.6e^{-0.1947\times t}\\\\40 = 58.6e^{-0.1947\times t}\\\\ e^{-0.1947\times t}= \dfrac{40}{58.6}\\\\ e^{-0.1947\times t}=log \dfrac{40}{58.6}\\\\Taking \ log \ on \ both \ side\\\\-0.1947 \times t = 0.38\\\\t = \dfrac{0.38}{0.1947}\\\\t = 1.95 \ hour$

The time of death is approximate 2 hours.

Therefore,

The approximate time of death is,

10 -2 = 8 a.m.

Hence, the approximate time of death is 8 a.m.

To know more about Newton's law click the link given below.

link

answered: cherry12345627

The formula we use for this is $T(t)= T_{r} +( T_{0} - T_{r} )e ^{-kt}$ , where T(t) is the temp after the cooling has taken place, $T_{r}$ is temp of the room, $T_{0}$ is the initial temp of the body, and t is the time in hours. "e" is Euler's number. Out T(t) = 80°, our $T_{r}$ is 40°, the initial temp of the body is 98.6°, and t is what we are solving for. So our equation then looks like this: $80=40+(98.6-40)e ^{-.1947t}$ . We will simplify inside the parenthesis first, of course, to get this: $80=40+58.6e ^{-.1947t}$ . Subtract 40 from both sides to get $40=58.6e ^{-.1947t}$ . Divide both sides by 58.6 to get $.68259385=e ^{-.1947t}$ . You're probably in logs right now in math, so you should be aware of the fact that a natural log "undoes" Euler's number, so we will take the natural log of both sides to move that t down into a place where we can work with it a bit easier. ln(.68259385)=-.1947t. Take the natural log of that decimal and get -.3818552424= -.1947t. Divide both sides by -.1947 to get a t value of 1.96 hours. If we subtract 1.96 hours from 10am we would get that the time of death was just about 8:03am

answered: Guest

step-by-step explanation:

we can use this expression to calculate the energy gain as a particle moves with a field or the energy loss as it moves against it. (note that it is also used to define the electron-volt, a unit of energy equal to that gained by an electron as it falls through a pd of 1 v, i.e. w = 1 ev = 1.6 10-19 c 1 v = 1.6 10-19j).in fact this expression is really nothing more than the statement that potential is the potential energy per unit charge. in this case, v= w/qis simply stating that the change in potential energy(or work done) per unit charge is equal to the change in potential (or potential difference), v.student questions: uniform electric fields2electron beamcathode+5 kvanode0 v

answered: Guest

step-by-step explanation:

because 1/3 is a fraction. we can tell because there is a divisor symbol between the 1 and the 3. if we were to add 2 fractions together, we would add the numerators, which is the number on top, but not the denominators, which is the number on the bottom

1/3+1/3=2/3

hope this !

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Abody was found at 10 a. m. in a warehouse where the temperature was 40of. the medical examiner foun...