If a pair of parallel lines are rotated

A roast turkey is taken from an oven when its temperature has reached 185 degrees F and is placed on a table in a room where the

Vedmedyk [2.9K]

(a) Using Newton's Law of Cooling, $\dfrac{dT}{dt} = k(T - T_s)$ , we have $\dfrac{dT}{dt} = k(T - 75)$ where T is temperature after T minutes.
Separate by dividing both sides by T - 75 to get $\dfrac{dT}{T - 75} = k dt$ . Integrate both sides to get $\ln|T - 75| = kt + C$ .

Since $T(0) = 185$ , we solve for C:
$|185 - 75| = k(0) + C\ \Rightarrow\ C = \ln 110$
So we get $\ln|T - 75| = kt + \ln 110$ . Use T(30) = 150 to solve for k:
$\ln| 150 - 75 | = 30k + \ln 110\ \Rightarrow\ \ln 75 - \ln 110= 30k \Rightarrow \\ k= \frac{1}{30}\ln (75/110) = \frac{1}{30}\ln(15/22)$

So

$\ln|T - 75| = kt + \ln 110 \Rightarrow |T - 75| = e^{kt + \ln110} \Rightarrow \\ \\
|T - 75| = 110e^{kt} \Rightarrow T - 75 = \pm110e^{(1/30)\ln(15/22)t} \Rightarrow \\
T = 75 \pm110e^{(1/30)\ln(15/22)t}$

But choose Positive because T > 75. Temp of turkey can't go under.

$T(t) = 75 + 110e^{(1/30)\ln(15/22)t} \\
T(45) = 75 + 110e^{(1/30)\ln(15/22)(45)} = 136.929 \approx 137{}^{\circ}F$

(b)

$T(t) = 75 + 110e^{(1/30)\ln(15/22)t} = 75 + 110(15/22)^{t/30} \\
100 = 75 + 110(15/22)^{t/30} \\
25 = 110(15/22)^{t/30} 
\frac{25}{110} = (15/22)^{t/30} \\
\ln(25/110) / ln(15/22) = t/30 \\
t = 30\ln(25/110) / ln(15/22) \approx 116\ \mathrm{min}$

Dogs of the AMS.

4 0

3 years ago

Kerri went shopping for her birthday party and bought seven 2-liter bottles of soda. If only five bottles of soda were consumed

alexira [117]

Answer:

4 liters

Step-by-step explanation:

2 bottles of soda are left

each bottle of soda has 2 liters

so 2 x 2 =4

7 0

2 years ago

(1) Factor the GCF out of the trinomial on the left side of the equation. (2 points: 1 for the GCF, 1 for the trinomial) 2x²+6x-

Tanya [424]

Step-by-step explanation:

(1) Factor the GCF out of the trinomial on the left side of the equation. (2 points: 1 for the GCF, 1 for the trinomial) 2x²+6x-20=0

2x²+6x-20

2(x²+3x-10)

the factors are 2 and (x²+3x-10)

(2) Factor the polynomial completely. (4 points: 2 point for each factor)

2(x²+3x-10)

2(x²-2x+5x-10)

2(x(x-2) + 5(x-2)) group like terms

2(x+5)(x-2)

(3) If a product is equal to zero, we know at least one of the factors must be zero. And the constant factor cannot be zero. So set each binomial factor equal to 0 and solve for x, the width of your project. (2 points: 1 point for each factor)

constant = 2 cannot be zero

the other factors are (x+5) and (x-2)

(x+5)=0 => x= -5

or

(x-2)=0 => x=2

(4) What are the dimensions of your project? Remember that the width of your project is represented by x. (2 points: 1 point for each dimension)

thank you so much, sorry if it's a little confusing!!

(it is indeed confusing, because physical dimensions cannot be negative)

The dimensions of the project (assumed a rectangle) are +2 and -5

3 0

3 years ago

A shark is swimming 60 feet below the surface of

Charra [1.4K]

Answer:

a

Step-by-step explanation:

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8 0

2 years ago

Factor each expres<br>k. 16 + 4x

tia_tia [17]

Answer:

4(4 + x)

Step-by-step explanation:

The only way to factor this expression is to take out the 4

16 + 4x

4(4 + x)

Answer: 4(4 + x)

4 0

3 years ago