The radius of a sphere is decreasing at a rate of 2 centimeters per second. At the instant when the radius of the sphere is 3 centimeters, what is the rate of change, in square centimeters per second, of the surface area of the sphere? (The surface area S of a sphere with radius r is S = 4πr2.)
Answer:
The rate of change of the surface area of the sphere is;
-48π cm^2/s
Step-by-step explanation:
Here, we want to calculate dA/dt
Mathematically that will be;
dA/dt = dA/dr * dr/dt
From the question;
dr/dt = -2 cm/s
dA/dr = 8πr
So dA/dt will be;
-2cm/s * 8πr = -16 πr cm/s where r is 3 cm
So;
dA/dt = -48π cm^2/s
Using implicit differentiation, it is found that the rate of change of the surface area of the sphere is of -151 square centimetres per second.
The surface area of an sphere of radius r is given by:
[tex]S = 4\pi r^2[/tex]
Applying implicit differentiation, the rate of change is given by:
[tex]S = 8\pi r\frac{dr}{dt}[/tex]
For this problem:
The radius of a sphere is decreasing at a rate of 2 centimetres per second, hence [tex]\frac{dr}{dt} = -2[/tex]It also is of 3 centimetres, hence [tex]r = 3[/tex]The rate of change is of:
[tex]S = 8\pi(3)(-2) = -48\pi = -151[/tex]
The rate of change of the surface area of the sphere is of -151 square centimetres per second.
A similar problem is given at https://brainly.com/question/11496075
I really need help......
Given f(x) = 4x + 10, the value of f(-2) is?
What is the area of the triangle?
A. 8.64 ft2
B. 10.8 ft2
C. 14.4 ft2
D. 17.28 ft2
Answer: 8.64
Step-by-step explanation:
3.6 * 4.8 = 17.28
17.82/2 = 8.64
Answer:
A. 8.64 ft²
Step-by-step explanation:
The equation for the area of a triangle is A = 1/2bh
b is base and in this case 4.8
h is height and in this case 3.6
A = 1/2 (3.6)(4.8)
A = 8.64
Hope this helped :)
plss answer it is so important
Answer:
1. (100-5) × (100+3) = 10000 + 300 - 500 - 15
=> 10300 - 515 = 9785
2. (500+1) × (500+2) = 250000 + 1000 + 500 + 2
=> 251502
which statement is true?
PLZ HELP IM TWO WEEKS BEHIND THE SCHOOL CALLED MY MOM
Which describes dependent events?
drawing a blue marble and a yellow marble at the same time from a bag of marbles
drawing the ace of spades from a deck of cards, putting it back into the deck, and
drawing the king of spades.
rolling a six-sided number cube and getting an even number, then rolling the same six-sided number cube and getting an even number again
flipping two coins at the same time and getting heads on one and tails on the other
Answer: Drawing a blue marble and a yellow marble at the same time from a bag of marbles is the example of dependent events.
Step-by-step explanation: When the cards are replaced, or flipping coins or rolling dice, the outcome of the first event does nor affect the probability of the next event.
Drawing two marbles at the same time is essentially the same as drawing one and Not replacing it and then drawing the second one. The number of marbles left affects the probability.
Answer:
A
Step-by-step explanation:
The price of a cd was decreased by 20% to £7.68. What was the price before the decrease?
Help me and I’ll give BRAINLEST
Answer:
The expression I got is (12d+12m+3a+6c)
WILL GIVE BRAINLIEST Bryan owes the bank $7. He gets paid $35 for
babysitting and deposits it into his account. What will
his bank balance show?
Answer:
$28
Step-by-step explanation:
Angelo grows vegetables and sells them at a farmers'
market. The price of 2 cucumbers and I pepper is
$3.15, and the price of 3 cucumbers and 2 peppers is
$5.35. Based on this pricing, what would be the price,
in dollars, of 4 cucumbers and 3 peppers?
Answer:
$7.55
Step-by-step explanation:
We can solve this by using a system of equations. The equations would be set up like this:
[tex]2c + p = 3.15\\3c + 2p = 5.35\\[/tex]
Let's isolate a variable in the first equation:
[tex]p = -2c + 3.15[/tex]
Now we can plug this in to the second equation:
[tex]3c + 2(-2c + 3.15) = 5.35\\3c - 4c + 6.3 = 5.35\\-c + 6.3 = 5.35 \\-c = -.95\\c = .95[/tex]
Now that we have found c we can find p by plugging c in to an equation
[tex]2(.95) + p = 3.15\\1.9 + p = 3.15\\p = 1.25[/tex]
We have found both variables now we can use the following equation to answer the question:
[tex]4c + 3p = ?\\4(.95) + 3(1.25) = ?\\3.8+3.75 = 7.55[/tex]
Therefore, the price in dollars of 4 cucumbers and 3 peppers is $7.55.
I hope this helps!!
- Kay :)
Every day kianna practices softball and piano each day she practices for 2 hours if after 7 days she practiced both softball and piano for a total of 24.5 hours how many hours per day did kianna ptactice piano
Answer: 1.5 hours
Step-by-step explanation:
Softball was practiced for 2 hours each day.
After 7 days she must have practiced it for;
= 7 * 2
= 14 hours
She practiced both piano and softball for a total of 24.5 hours. She therefore practiced piano for;
= 24.5 - 14
= 10.5 hours
If in 7 days she practiced piano for 10.5 hours, everyday she must have practiced piano for;
= 10.5/7
= 1.5 hours
Where would a car traveling up a hill have the most potential energy?
A. At the bottom
B. Halfway to the top
C. At the top
D.Halfway to the bottom
E. it is always the same
Answer:
At the top
Step-by-step explanation:
When your car stops at the top of the hill, it has the most potential energy.
determine if graph is a function
PLEASE HELP
Write an equation of the line in slope-interecpt form that is perpendicular to the line below and goes through
the point below:
perpendicular to 2 – 3y = 3 and goes through (5, -9)
Answer:
Sure!
Step-by-step explanation:
On what intervals is the graph increasing and or decreasing
Answer:
Using interval notation, it is described as increasing on the interval (1,3). Decreasing: A function is decreasing, if as x increases (reading from left to right), y decreases.
Step-by-step explanation:
How much simple interest would $1 ,400 earn in 12 months at an interest rate of 3.25%?
Answer:
$45.50
Step-by-step explanation:
Interest = Principal x rate x time (in years)
I = 1400 x .0325 x 1
Answer:
$45.50
Step-by-step explanation:
Ian bought a cup of coffee. At first, he sipped slowly. As it cooled down, he drank more quickly. The last bit was cold, and he dumped it out
Answer:
ian just wasted the last bit of coffee.
Step-by-step explanation:
the product of the roots of a quadratic equation 2x²-5x+3=0 is 5/2 if it is correct give reason
9514 1404 393
Answer:
It is incorrect. The product is 3/2.
Step-by-step explanation:
The factored form of a quadratic with roots p and q can be ...
a(x -p)(x -q) = ax² -a(p+q) +apq
Then the product of the roots is the ratio of the constant to the leading coefficient:
pq = (apq)/a
In the given quadratic, that product is ...
pq = 3/2 . . . . . . not 5/2
The statement that the product of roots is 5/2 is incorrect. That value does not have the required relationship to the coefficients of the quadratic.
Find the value of x. Give reasons to justify your solution-
Answer:
x = 34
Step-by-step explanation:
∠ PSR and ∠ TSU are vertical angles and congruent, then
∠ PSR = 4x, thus ∠ PSQ = x
The exterior angle of a triangle is equal to the 2 opposite interior angles.
∠ SQR is an exterior angle of Δ PQS , thus
x + x = 68
2x = 68 ( divide both sides by 2 )
x = 34
Answer:
X = 34°
Step-by-step explanation:
In order to solve this question we will need to know the following, when two lines intersect the opposite angles at that point are equal to each other, that the sum of all angles of a triangle is 180 degrees, and that the angle of a straight line is equal to 180 degrees.
Frist we will have to notice that ∠TSU is equal to ∠PSR, because they are opposite to each other (If you would like to understand this more you can research on a topic call "vertical angels"). Now it is important to understand the following.
∠PSR = ∠PSQ + QSR
Since ∠PSR = ∠TSU = 4x, ∠QSR = 3x ⇒
⇒ ∠PSR = ∠PSQ + QSR
4x = ∠PSQ + 3x
4x - 3x = ∠PSQ
x = ∠PSQ
Now, since the sum of all angles in a triangle is equal to 180 we can now say the following:
∠QPS + ∠PSQ + ∠PQS = 180°
In order to find out what PQS is equal to we need to use our knowledge about the angel of a strait line (the angel of a strait line is equal to 180°).
So now we can say the following:
180° = ∠PQS + SQR
∠PQS = 180° - ∠SQR
Since we know that ∠SQR = 68° ⇒
⇒∠PQS = 180° - ∠SQR
∠PQS = 180° - 68°
∠PQS = 112°
Since ∠QPS = x, PSQ = x, and ∠PQS = 112° ⇒
⇒ ∠QPS + ∠PSQ + ∠PQS = 180°
x + x + 112° = 180°
2x = 180° - 112°
2x = 68°
x = 34°
Please help me asap! pleaseee
4 / 1.21 what’s the answer?
Answer:
3.30
Step-by-step explanation:
Please help me! 8 pts and brainliest!! please
One angle is a complementary pair is twice as large as the other. What is the measure of the larger angle?
a. 30°
b. 60°
c. 90°
d. 120°
Answer:
60 degrees
Step-by-step explanation:LARGE ANGLE...60-degrees
So, we have x + 2x = 90. Solving for x, we get x = 30. Since the first angle was called x, that means it's measurement is 30°. The second angle, 2x, is just twice the first angle, so its measurement is 60°
Help I’m being timed!!!!
Answer:
C the 3 one is the answer
Answers choices are in the picture
Answer: I believe the answer is b.
Can someone please explain this
Answer: orange, correct me if i am wrong
Step-by-step explanation:
What is the value of r in the equation?
-1.5(4-r)--12
-6
O4
O
4
O6
Answer:
I am going to say 6 , please let me know if I am wrong :)
Lamar planted 56 flowers in his garden. The ratio or orange to yellow flowers planted was 25
2
5
. How many yellow flowers did Lamar plant?
Answer:
I think its 31
Step-by-step explanation:
because the ratio was 25/56 of orange flowers,
so the rest of them are yellow
I WILL MARK BR HELP PLZ
Answer:
C)8
Step-by-step explanation:
So you are supposed to fill in that bottom equation with the top to get
-4x=x2+2x+8
+4x
x2 +6x+8
(x+4)(x+2) (remember x=-2,-4)
y=-4x
y=-4(-4)
y=16
y=-4x
y=-4(-2)
y=8
Select the correct answer.
Write an expression to represent the product of -3 and the square of a number decreased by 8.
How many terms are in your expression?
4
2
3
1
Answer:2
Step-by-step explanation: