The temperature of a cup of coffee varies according to Newton's Law of Cooling: dT dt equals negative k times the quantity T minus A, where T is the temperature of the coffee, A is the room temperature, and k is a positive constant. If the coffee cools from 100°C to 90°C in 1 minute at a room temperature of 25°C, find the temperature, to the nearest degree Celsius of the coffee after 4 minutes.

74
67
60
42

Answers

Answer 1

Answer:

  (b)  67

Step-by-step explanation:

A solution to the differential equation describing the temperature according to Newton's Law of Cooling could be written as ...

  T = (final temp) + (initial difference)×(decay factor)^t

where the decay factor is the fraction of change during 1 unit of time period t.

__

Here, the initial difference of 100-25 = 75 degrees decays to 90-25 = 65 degrees in 1 minute. So, the units of t are minutes, the decay factor is 65/75, the initial difference is 75 degrees, and the final temperature is 25 degrees. That lets us write the equation as ...

  T = 25 +75(65/75)^t

Then for t=4, the temperature is ...

  T = 25 +75(13/15)^4 ≈ 67.3 . . . . degrees

After 4 minutes the temperature of the coffee is about 67 degrees.

The Temperature Of A Cup Of Coffee Varies According To Newton's Law Of Cooling: DT Dt Equals Negative

Related Questions

A flower bed is in the shape of a triangle with one side twice the length of the shortest side and the third side is 29 feet more
than the length of the shortest side. Find the dimensions if the perimeter is 141 feet.
What is the length of the shortest side?
The length of the shortest side is
(1)
What is the length of the second side?
The length of the second side is
(2)
What is the length of the third side?
The length of the third side is
(3)

Answers

Answer:

Step-by-step explanation:

8y8yy89y99u98u89y7t8y7i6u7i9jo

Each batch of cookies is 8.9 oz. What is the weight of 2.5 batches of cookies

Answers

Answer:22.25 oz

Step-by-step explanation:

1 batch of cookies = 8.9 oz

2.5 batches of cookies = x oz

cross multiply

1x=8.9(2.5)

x=22.25 oz

Find the value of xxx, yyy, and zzz in the parallelogram below.

Answers

Answer:

Step-by-step explanation:

Opposite angles of a parallelogram are congruent, so:

[tex]112=y-9 \longrightarrow y=121[/tex]

and adjacent angles are supplementary, so:

[tex]112+x+1=112+z+3=180 \longrightarrow x=67, z=65[/tex]

Determine whether the pair of triangles is congruent.

Choose the correct answer below.

Congruent
Not congruent

Answers

Answer:

not congruent

Step-by-step explanation:

congruent is just a fancy way of saying the same in geometry. so to check if its congruent, see if all side lengths correspond to another side length on the other triangle. they do not, so they can't be congruent

hope this helped :)

The mass of a carbon-12 atom is 1.99\times 10^{-23}1.99×10

−23

grams. The mass of a neutron is 1.68\times 10^{-24}1.68×10

−24

grams. How many times greater is the mass of a carbon-12 atom than the mass of a neutron? Write your answer in standard notation, rounding to the nearest tenth.

Answers

Answer:

If the mass of one electron is 9.11 x 10-28 g, and you are looking for the mass of a mole of electrons, you need to understand Avogadro's number.  One mole is 6.02 x 1023 particles.  So you will have to multiply (6.02 x 1023) x (9.11 x 10-28 g) to get your answer of  5.48 x 10-4 grams (answer rounded to significant figures)

Step-by-step explanation:

1.2 x 10¹ times  greater is the mass of a carbon-12 atom than the mass of a neutron

What is Division?

A division is a process of splitting a specific amount into equal parts.

To find the ratio of the mass of a carbon-12 atom to the mass of a neutron, we can divide the mass of carbon-12 by the mass of a neutron:

(1.99×10⁻²³ grams) / (1.68×10⁻²⁴ grams)

= 11.8 grams

This means the mass of a carbon-12 atom is 11.8 times greater than the mass of a neutron. Written in standard notation and rounded to the nearest tenth, the answer is 1.2 x 10¹

Hence, 1.2 x 10¹ times  greater is the mass of a carbon-12 atom than the mass of a neutron

To learn more on Division click:

https://brainly.com/question/21416852

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Use the volume formula to find the volume of the prism.




A. 21 cubic units B. 42 cubic units C. 27 cubic units D. 9 cubic units

Answers

Answer:

D Because

Step-by-step explanation:

1/2 +1/2 is 1 so 1+1+3+4 is 9

HOPE THIS HELP! :)

Let f(x) = logx

What is the average rate of change of f(x) from 4 to 6?

Round to the nearest hundredth.

(a.) 0.09
(b.) 0.18
(c.) 0.20
(d.) 0.41

Answers

(a.) 0.09

equation:

f(x) = log(x)

rate of change:

[tex]\sf \rightarrow \sf \dfrac{y_2-y_1}{x_2-x_1}[/tex]

[tex]\sf \rightarrow \sf \dfrac{log(4) -log(6)}{4-6}[/tex]

[tex]\sf \rightarrow 0.088[/tex]

[tex]\sf \rightarrow 0.09[/tex]

Answer:

[tex]A.\: 0.09[/tex]

Step-by-step explanation:

Rate of Change is: [tex]\frac{y{_1-y{_2} } }{x_2-x_1}[/tex]

[tex]\frac{log(4)-log (6)}{4-6}[/tex]

[tex]0.088[/tex]

[tex]0.09[/tex]

Please help asap! I will gave brainlest!

Answers

Answer:

√2 + √6 / 4

Step-by-step explanation:

We know cos(-θ) = cosθ.

Therefore, cos(-15°) = cos15°.

cos15° = cos(45 - 30)

cos15° = cos45cos30 + sin45sin30cos15° = (1/√2)(1/2) + (1/√2)(√3/2)cos15° = 1/2√2 + √3/2√2cos15° = √3 + 1 / 2√2cos15° = (√3 + 1)(√2) / 4cos15° = √2 + √6 / 4Option 1

Two balls are placed in a box according to the following process: 1. A fair coin is tossed. A white ball is placed in the box if a head occurs, otherwise a red ball is placed in the box. 2. The fair coin is tossed again. A red ball is placed in the box if a tail occurs, otherwise a white ball is placed in the box. Balls are drawn from the box three times in succession (always with replacing the drawn ball back in the box). On all three occasions a red ball is drawn from the box. There are two pieces of information available: the process by which balls are placed in the box and the 3 observations of a ball drawn from the box. Making use of all relevant available information, what is the probability that both balls in the box are red

Answers

Answer:

The probability that both balls in the box are red given that all three occasions a red ball is drawn from the box is [tex]\frac{4}{5}[/tex]

Step-by-step explanation:

Let RRR be the event in which red Balls are drawn from the box three times in succession

Let rr be the event that two red balls are placed in a box

Let rw be the event the first red ball was placed and then white ball was placed

Let wr be the event the first white ball was placed and then red ball was placed

Let ww be the event that two white balls are placed in a box

Now we know that :

[tex]P(rr)=P(rw)=P(wr)=P(ww)=\frac{1}{4}[/tex]

Probability of getting red Balls three times in succession given that both are placed red balls in box:

[tex]P(RRR|rr)=1[/tex]

Probability of getting red Balls three times in succession given that one ball is red and another is white in a box

[tex]P(RRR|wr)=P(RRR|rw)=\frac{1}{2^3}=\frac{1}{8}[/tex]

Probability of getting red Balls three times in succession given that both are placed white balls in box:

[tex]P(RRR|ww)=0[/tex]

Now we are supposed to find the probability that both balls in the box are red given that  all three occasions a red ball is drawn from the box i.e. P(rr|RRR)

So, we will use bayes theorem

[tex]P(rr|RRR)=\frac{P(RRR|rr) P(rr)}{P(RRR|rr) P(rr)+P(RRR|rw) P(rw)+P(RRR|wr) P(wr)+P(RRR|ww) P(ww)}\\P(rr|RRR)=\frac{1 \times \frac{1}{4}}{1 \times \frac{1}{4}+\frac{1}{8} \times \frac{1}{4}+\frac{1}{8} \times \frac{1}{4}+0 \times \frac{1}{4}}\\\\P(rr|RRR)=\frac{\frac{1}{4}}{\frac{5}{16}}\\\\P(rr|RRR)=\frac{4}{5}[/tex]

Hence the probability that both balls in the box are red given that all three occasions a red ball is drawn from the box is [tex]\frac{4}{5}[/tex]

Which of the following would be appropriate to measure in centimeters

Answers

Answer:

c

Step-by-step explanation:

The speed of a tidal wave, s, in hundreds of miles per hour can be modeled by the equation, [tex]s=\sqrt{t} -2t+6[/tex] , where t represents the time from its origin in hours. The graph of the tidal wave is shown.

Answers

Using it's concept, it is found that the domain of the function regarding the speed of the tidal wave is explained by:

[0, 4]: relating to the time of the tidal wave from it's origin in hours, restricted by the inability for the speed to be lees than zero.

What is the domain of a function?

It is the set that contains all possible input values for the function. In a graph, it is given by the x-values, that is, the horizontal axis values.

In this graph, the horizontal axis assumes values between 0 and 4, which is the time after the wave, and considering that the wave cannot be less than zero. Hence, the correct option is:

[0, 4]: relating to the time of the tidal wave from it's origin in hours, restricted by the inability for the speed to be lees than zero.

More can be learned about the domain of a function at https://brainly.com/question/25897115

Solve
8x + 12x = 180 what does x equal?

Answers

Answer:

8x + 12x = 180

x=9

Step-by-step explanation:

Answer:

x = 9

Step-by-step explanation:

8x + 12x = 180

20x = 180

x = 180/20

x = 9

Please mark me the brainliest!?!

Factor 48e+180 using greatest common factor

Answers

12

48 = 24 × 31

180 = 22 × 32 × 51

QUESTION 1
The general term of the sequence is given by Tn= an + bn + c T2-T1 = 4; T3; -T2 = 6; T4-T3 = 8 and T2 = 6

1.1 Calculate a, b and c ​

Answers

Answer:

The general term of the sequence is given by

T

n

=

a

n

2

+

b

n

+

c

The general term of the sequence is given by

T

n

=

a

n

2

+

b

n

+

c

Calculate a,b and c

Determine the 12th term of the sequence.

grade12 general-term sequence series

Share your questions and answers with your friends.

answer comment

1 Answer

0

0

T3 - 6=6

T3=12

then T2-T1=4

6-T1=4

T1=2

T4-T3=8

T4-12=8

T4=20

Therefore terms= 2,6,12,20

1st difference= 4,6,8

2nd difference= 2,2,....

2a=2

a=1

3a+b=4

3(1) + b=4

b= 1

a+b+c= 2

c= 2-1- 1= 0

giving Tn= n^2 + n

T12 = 12^2 + 12 = 156

A hall is thrown straight up, from 3 m above the ground, with a velocity of 14m/s. When does it hit the ground? Use the vertical motion formula.

Answers

In this question, to find the total height first, we must also take into consideration the acceleration due to gravity as well. To find the distance by which acceleration due to gravity pulls the ball down must know the Initial velocity.

In the answer key, it says that gravity changes the ball's height by a distance of -5t^2

Is initial velocity in this question 0 or 14m/s? Because if it is 14, then gravity should change the balls position by -(14+5t^2), not -5t^2, because if I remember correctly, the formula for finding distance is vt(initial velocity)+(1/2)at^2 ,and not just (1/2)at^2

I have 7 hundreds blocks, 5 tens blocks, and 8 ones blocks. I use my blocks to model two 3-digit number. What could my two number be?

Answers

758

(if you don't have to use all the blocks)

757

750

708

754 etc

For a project in his Geometry class, Elijah uses a mirror on the ground to measure the height of his school building. He walks a distance of 8.25 meters from the school, then places a mirror on flat on the ground, marked with an X at the center. He then steps 0.8 meters to the other side of the mirror, until he can see the top of the school clearly marked in the X. His partner measures the distance from his eyes to the ground to be 1.45 meters. How tall is the school? Round your answer to the nearest hundredth of a meter.

Answers

The school is about 14.95 meters tall, and the mirror is 8.25 meters from the school.

What is trigonometric ratio?

Trigonometric ratio is used to show the relationship between the sides and angles of a right angled triangle.

Let Ф represent the angle Elijah makes with the ground, hence:

tanФ = 1.45/0.8

Ф = 61.11°

The angle of elevation to the building is 61.11°. Let h represent the height of the building.

tan(61.11°) = h/8.25

h = 14.95

The school is about 14.95 meters tall, and the mirror is 8.25 meters from the school.

Find out more on trigonometric ratio at: https://brainly.com/question/24349828

Which of the following is true?

A |−5| < 4
B |−4| < |−5|
C |−5| < |4|
D |−4| < −5

Answers

B is true

Step-by-step explanation:

because no number with them to lines can be a negative

Do you know the tricks to multiplying variables?

Answers

Answer:

yes I know how to to multiple variables.

A triangular prism with 5 faces.

A triangular prism has faces.

Answers

Answer:

Pentahedron

Step-by-step explanation:

A triangular prism with 5 faces is called Pentahedron.

It has 5 faces,  6 vertices and 9 edges.

5 faces -  Two are triangular faces and three are rectangular faces.

Answer:

its has 5 faces

Step-by-step explanation:

please help me with this

Answers

Answer:

y-5=3/4(x-6)

Step-by-step explanation:

The picture you posted is a bit unclear and difficult to look at, but that's alright.

This is a simple question if you understand that the point slope for equation is: y-y1 = m(x-x1).

m is the slope and (x1,y1) is a point on the graph.

So, if you input the point (6,5) on the graph, it works.

You can double check with the other equations to see that they are all wrong!

the selling price of a product is $20 and the markup is $4 What percentage of the selling price does the markup represent

Answers

Answer:

20%

Step-by-step explanation:

The ratio of 20 to 4 can be simplified to 5:1, by switching it around, we get 1/5. 1/5 as a percentage can be expressed as 20%

Answer:

20%

Step-by-step explanation:

Given the following question:

20% of 20

To find the answer we will use the formula to calculate percentages.

[tex]\frac{p\times n}{100}[/tex]
[tex]\frac{20\times20}{100}[/tex]
[tex]20\times20=400[/tex]
[tex]400\div100=4[/tex]
[tex]=4[/tex]

20% of 20 is 4, which means your answer is "20%."

Hope this helps.

What is the value of the expression?

(7 2/3−4 8/9)+(5 2/3−2 1/2)

Enter your answer as a mixed number in simplest form by filling in the boxes.

Answers

Answer:

  5 17/18

Step-by-step explanation:

Your calculator can help with this.

__

The integer parts of the mixed numbers can be dealt with separately. The fractional parts are added and subtracted using a common denominator. Here, that denominator is the least common multiple (LCM) of 2, 3, and 9, so is 18.

  ((7 2/3) -(4 8/9)) +((5 2/3)) -(2 1/2))

  = (7 2/3) +(5 2/3) -((4 8/9) +(2 1/2))

  = 12 4/3 -(6 +8/9 +1/2)

  = 13 6/18 -(6 +16/18 +9/18)

  = 13 6/18 -(6 +25/18) = 13 6/18 -(7 7/18)

  = (13 -7) +(6/18 -7/18)

  = 6 -1/18

  = 5 17/18

__

Additional comment

Doing the math in the manner shown above means you can mostly do it without a calculator. If you like, you can convert all of the numbers to improper fractions, then add those. This often requires a calculator.

  = (138/18 -88/18) +(102/18 -45/18)

  = 50/18 +57/18

  = 107/18 = 5 17/18

(5,-5) (6,-6) (7,-7) (8,-8) what is the slope

Answers

The correct answer it’s 1

Answer:

i think its straight line

Need help not sure if I got this right???????????

Answers

Yes it is right. Thats how you do that probably band skip school and ya get your class code for your the wym was your class code class starts tomorrow morning so I gotta get to

maths I need help asap it's about sequence and functions good rewards!​

Answers

Answer:

a₄ = 50

Step-by-step explanation:

work back from the seventh term a₇ using the reverse of the term to term rule , that is

divide by 2 then subtract 3

a₇ = 442

a₆ = 442 ÷ 2 - 3 = 221 - 3 = 218

a₅ = 218 ÷ 2 - 3 = 109 - 3 = 106

a₄ = 106 ÷ 2 - 3 = 53 - 3 = 50

Answer:

[tex]a_{4}=50[/tex]

Step-by-step explanation:

[tex]a_{4} = 50[/tex]

a₇ = 442

a₆ = 442 ÷ 2 - 3 = 221 - 3 = 218

a₅ = 218 ÷ 2 - 3 = 109 - 3 = 106

a₄ = 106 ÷ 2 - 3 = 53 - 3 = 50

Find the area of the sector. Round your answer to nearest tenth.

Answers

[tex]\textit{area of a sector of a circle}\\\\ A=\cfrac{\theta \pi r^2}{360}~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=20\\ \theta =90 \end{cases}\implies \begin{array}{llll} A=\cfrac{(90)\pi (20)^2}{360}\implies A=100\pi \\\\\\ A\approx 314.2 \end{array}[/tex]

How do you do this question?

Answers

Answer: Diverges

This series diverges by the limit test (some books may call it the nth term test).

Recall the limit test is the idea if the sequence doesn't converge to 0, then the series diverges.

In this case, the sequence converges to n/(7n) = 1/7 since all we are about are the leading terms when n gets very large.

After some very large n value, we're effectively adding on 1/7 or very close to it, each time. The infinite sum does not approach a fixed value. It keeps growing forever.

The following histogram shows the relative frequencies of the hieight recorded to the nearest inch of population of women the mean of the population is 64.97 inches and the standard deviation is 2.66 inches

Answers

The following histogram shows the relative frequencies of the height recorded to the nearest inch of population of women the mean of the population is 64.97 inches and the standard deviation is 2.66 inches

(a) Based on the histogram, what is the probability that the selected woman will have a height of at least 67 inches? Show your work

Answer:

0.22268

Step-by-step explanation:

z-score is z = (x-μ)/σ,

where x is the raw score

μ is the population mean

σ is the population standard deviation.

(a) Based on the histogram, what is the probability that the selected woman will have a height of at least 67 inches? Show your work

At least means equal to or greater than 67 inches

z = 67 - 64.97/2.66

z = 0.76316

P-value from Z-Table:

P(x<67) = 0.77732

P(x>67) = 1 - P(x<67) = 0.22268

The probability that the selected woman will have a height of at least 67 inches is 0.22268

In which number is the digit 5 one hundred times larger than it is in the number 253

Answers

Answer:

The 5 would be in the Thousands place

Step-by-step explanation:

Hope this helps any

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