Solution :
A). As the time passes the temperature of the coffee tends to acquire the temperature of the room, so the limiting value of the temperature of the coffee is 20°C. i.e.
[tex]$\lim_{t \to \infty} T(t)=20$[/tex]
B). And limiting value of rate of cooling is given by :
[tex]$\lim_{t \to \infty} \ \frac{dT}{dt} =\lim_{t \to \infty} \ [k(T-T_{room})] $[/tex]
[tex]$=k . \lim_{t \to \infty} (T-T_{room})$[/tex]
[tex]$=k .[ \lim_{t \to \infty} T-\lim_{t \to \infty} T_{room}]$[/tex]
[tex]$=k.[T_{room}-T_{room}]$[/tex]
= k. 0
= 0
C). Given, [tex]$\frac{dT}{dt} = -1, $[/tex] when T(t) = 70° using this in the given equation,
-1 = k.(70-20)
k = -0.02
D). By Euler method, we get
[tex]$T_{n+1}=T_n + h \ f(t_n, T_n)$[/tex]
[tex]$t_{n+1}=t_n +h$[/tex]
where, [tex]$f(t,T) =k(T-T_{room})$[/tex]
= -0.02(T - 20)
We have [tex]$T_0 = 90^\circ$[/tex] at t = 0 and h = 2.
So [tex]$t_1 = 0+2 = 2$[/tex]
∴ [tex]$T_1=T_0 + h \ f(t_0,T_0)$[/tex]
= 90+2[-0.02(90-20)]
= 87.2
At [tex]$t_2 = 2+2 = 4$[/tex]
[tex]$T_2=T_1 + h \ f(t_1,T_1)$[/tex]
= 87.2+2[-0.02(87.2-20)]
= 84.51
At [tex]$t_3 = t_2+2 = 4+2=6$[/tex]
[tex]$T_3=T_2 + h \ f(t_2,T_2)$[/tex]
= 84.51+2[-0.02(84.51-20)]
= 81.93
At [tex]$t_4 = t_3+4 = 6+2=8$[/tex]
[tex]$T_4=T_3 + h \ f(t_4,T_4)$[/tex]
= 81.93+2[-0.02(81.93-20)]
= 79.45
At [tex]$t_5 = t_4+2 = 8+2=10$[/tex]
[tex]$T_5=T_4 + h \ f(t_4,T_4)$[/tex]
= 79.45+2[-0.02(79.45-20)]
= 77.07
So after 10 minutes, the temperature of the coffee will be 77.07°C.
Let me know guys pls
Answer:5
Step-by-step explanation:
Answer:
Step-by-step explanation:
x/35=15/25
x=35(15)/25
x=21
The carnival also offers two magic shows. The morning show is only 20 minutes and it costs $3.75. For the afternoon show, it is 35 minutes and costs $5.25. Which show would give you more for your money?
Answer:
35 minutes
Step-by-step explanation:
The carnival offers two magic shows
The morning show is for 20 mintes at $3.75
= 3.75/20
= 0.1875
The afternoon show is for 35 minutes at $5.25
= 5.25/35
= 0.15
Hence you pay a lesser amount for 35 minutes
How can you tell how many solutions a linear equation will have by looking at the equation?
Answer:
A system of two equations can be classified as follows
Step-by-step explanation:
If the slopes are the same but the y-intercepts are different, the system has no solution. If the slopes are different, the system has one solution. If the slopes are the same and the y-intercepts are the same, the system has infinitely many solutions.
Solve these with work shown please.
Step-by-step explanation:
substitute the value in the value of x and u will get the result.
For each statement, write what would be assumed and what would be proven in a proof by contrapositive of the statement. Then write what would be assumed and what would be proven in a proof by contradiction of the statement.
a. If x and y are a pair of consecutive integers, then x and y have opposite parity.
b. For all integers n, if n² is odd, then n is also odd.
Answer:
a)
Given Statement - If x and y are a pair of consecutive integers, then x and y have opposite parity.
Proof by Contrapositive:
Assumed statement: Suppose that integers x and y do not have opposite parity.
Proven Statement: x and y are not a pair of consecutive integers.
Proof -
x = 2u₁ , y = 2u₂
Then
(x, x+1) = (2u₁ , 2u₁ + 1) = (Even, odd)
If y = 2u₁ + 1
Not possible
⇒x and y are not a pair of consecutive integers.
Hence proved.
Proof by Contradiction:
Assumed statement: Suppose x and y are not a pair of consecutive integers.
Proven Statement: Suppose x and y do not have opposite parity.
Proof -
If x and y are not a pair of consecutive integers.
⇒ either x and y are odd or even
If x and y are odd
⇒x and y have same parity
Contradiction
If x and y are even
⇒x and y have same parity
Contradiction
(b)
Proof by Contrapositive:
Assumed statement: Let n be an integer such that n is not odd (i.e. n is an even integer)
Proven Statement: n² is not odd (i.e n² is even)
Proof -
Let n is even
⇒n = 2m
⇒n² = (2m)² = 4m²
⇒n² is even
Hence proved.
Proof by Contradiction:
Assumed statement: Let n be an integer such that n² be odd.
Proven Statement: suppose that n is not odd (i.e n is even)
Proof -
Let n² is odd
⇒n² is even
⇒n² = 2m
⇒2 | n²
⇒2 | n
⇒n = 2x
⇒ n is even
Contradiction
These are 2 questions please help me
Answer:
Step-by-step explanation:23
Sophia is a salesperson at a home improvement center. She is paid a monthly commission that is 7.5% of her first $1,000 in sales and
12% of the balance of her sales. Today she sold $1200. How much is her commission?
helen spent $7.75 to purchase 23 snacks for the club meeting. chips are
Select all sports that apply (you may select more than one). The underhand serve is used in...
Badminton
Tennis
Soccer
Pickleball
Voleybal.
Find the whole. 215% of what number is 172
Harriet worked out five times last week Each day, she ran on the treadmill and then walked for 20 minutes. She ran on the treadmill for the same amount of time each day. If she worked out for a total of 265 minutes, how much time was spent on the treadmill running each day?
Answer: it’s 13.25
Step-by-step explanation:
b) A car priced at $3600 is reduced by 25%.
What is the reduced price?
3600:25 =144
reduced price is 144$
In a scale drawing of a rectangular garden,
the length is 15 inches and the width is
9 inches. In the drawing, 2 inches represents
3 yards. What is the width of the actual
garden, in yards?
Answer:
width is 13.5 yards
Step-by-step explanation:
2" / 3 yds = 9" / 'x' yards
cross-multiply:
2x = 27
x = 13 1/2 yards
Sixty less than ten times ten
Answer:
40
Step-by-step explanation:
10x10=100
100-60=40
Hope this helps! :)
Wednesday, a local deli offered a lunch special consisting of a ham or roast beef sandwich with or without American cheese on toast, a roll, or a bagel. Thursday, the owner of the deli decided to offer customers the same options of meat and bread but let customers choose to have their sandwiches with or without either American or Swiss cheese.
How many more one meat, one cheese, one bread sandwich combinations are offered Thursday than Wednesday?
1
6
12
18
I think that A would be the correct answer.
Please Help, 20 points and brainiliest, URGENT.
Answer:
Step-by-step explanation:
∠ACB and ∠ECD are vertical angles, so ∠ACB = ∠ECD.
∠D = ∠B
∠A = ∠E
△ABC and △EDC are similar because they have the same angles.
pls guys tell me the answer pls
Answer:
Height = 7m
Step-by-step explanation:
Hope that helps!
Answer:
7m
Step-by-step explanation:
The mass of a basket containing three balls was 3.64 kg. The mass of the same basket and five balls is 5.26 kg. Find the mass of the empty basket in kilograms?
Answer:
1.21
Step-by-step explanation:
5.26 - 3.64 = 1.62
1.62 ÷ 2 because the difference between 3 and 5 is two, the mass of one apple is 0.81 because 1.62 ÷ 2 = 0.81
so now we know one apple weights 0.81
if we multiply that 0.81 x 3 it will equal 2.43, so now the three apples alone wiegh 2.43...so now we look at the total weight of the whole basket with three apples, which is 3.64,
3.64 - the weigth of the apples (2.43)
3.64 - 2.43 = 1.21
the basket alone wieghts 1.21
Sorry if that was too long just want you to understand it
In a softball league, 4 coaches are needed for every 28 players. If 84 players sign up for softball, how many coaches are needed?
Answer:
12 coaches
Step-by-step explanation:
If for every 28 players, 4 coaches are needed, for 84 (triple the amount) players, 12 coaches would be needed (triple the amount)
What is the slope of y = -x + 7?
Answer:
The slope is -1
WILL MARK BRAINLYIST
put median or altitude for the first part
Given that a linear function goes through the points (3,2) and (5, 6) determine the slope
of the line.
Answer:
2
Step-by-step explanation:
The formula of slope from 2 points is change in y divided by change in x, so you can apply that to this problem.
First, find the change in y between the two points. To do this, do y2 - y1.
y2 = 6 and y1 = 2, so you have 6 - 2 = 4.
Next, find the change in x between the two points. To do this, do x2 - x1.
x2 = 5 and x1 = 3, so you have 5 - 3 = 2.
All you're really doing here is finding the distance between the x values and the y values of the points, if that makes sense.
The last step is to do change in y divided by change in x, so 4 / 2 = 2.
This means that the slope of the line is 2.
A number that adds with 2/3 substrate 1/3 will be 8.What should be the number??
Answer:
The number is [tex]\frac{23}{3}[/tex]
Step-by-step explanation:
I am going to call the number x.
A number that adds with 2/3 subtract will 1/3 will be 8.
As an equation, this is:
[tex]x + \frac{2}{3} - \frac{1}{3} = 8[/tex]
Now we solve the equation to find x. So
[tex]x + \frac{2-1}{3} = 8[/tex]
[tex]x + \frac{1}{3} = 8[/tex]
[tex]x = 8 - \frac{1}{3}[/tex]
[tex]x = \frac{24}{3} - \frac{1}{3}[/tex]
[tex]x = \frac{24-1}{3}[/tex]
[tex]x = \frac{23}{3}[/tex]
The number is [tex]\frac{23}{3}[/tex]
1) Dan ate 1/12 of a pumpkin, while Sandy ate 1/2 of a pumpkin. In total, how much pumpkin did these two eat?
Answer:
1 pumpkin
Step-by-step explanation:
1/2 + 1/2 is 1. They ate 1 pumpkin in total.
The ratio of children to adults at a movie theater was 8:5. The theater sold 120 children tickets
that evening. How many adults attended the theater that night? How many tickets did the theater
sell altogether?
Answer:
75 adults
195 total tickets
Step-by-step explanation:
8:5
120:x
a. Draw a rectangle with an
area of 39 squares, and
perimeter of 32 units.
a
Answer:
It has side lengths of 3 and 13
Step-by-step explanation:
If it has an area of 39, then let the sides be x and y: thus we get the two relationships:
xy=39
2(x+y)=32
From the second equation, you get x+y=16. Now, rearrange to get y=16-x. You can now plug this into the first equation:
x(16-x)=39 -> 16x-x^2=39 -> x^2-16x+39=0 -> (x-3)(x-13)=0
This implies that x=3, or x=13, which further implies that the side lengths must be 3 and 13.
5. The perimeter of a polygon is__________ equal to 2w+21.
A. always
B. sometimes
C. never
lolamm ir
a regular polygon.
The mayor of a town has proposed a plan for the annexation of a new community. A political study took a sample of 800 voters in the town and found that 51% of the residents favored annexation. Using the data, a political strategist wants to test the claim that the percentage of residents who favor annexation is more than 47%. Determine the P-value of the test statistic. Round your answer to four decimal places.
hope this helps!!
mark me brainlist? this took a lil bit
pa help po dito please need Napo kase ehhh
Use the rectangle below to answer both part 1 and part 2
X+5
Part 1: Write an equation to find the value of x, if the area of the rectangle is 48 in?
Equation:
Part 2: What is the value of x, if the area of the retangle is 48 in2? Solve your equation from part 1.
X =
Blank 1:
Blank 2:
Answer:
i believe the equation is x = 48 ÷ 4 - 5
and x = 7
Step-by-step explanation:
you will need to take the are devided by width, because area is length times width. then subtract 5.
48÷4=12
12-5=7