1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
inn [45]
2 years ago
15

What is the circumference of a circle when the diameter is 8cm?

Mathematics
2 answers:
Paraphin [41]2 years ago
7 0

Answer:

the answer is 4cm circumference

loris [4]2 years ago
3 0

Answer:

C = 25.13cm

C = π d = π · 8 ≈ 25.13274cm

You might be interested in
What is the Product of x-3 and x-9​
Serggg [28]

Answer:

x^2-12x+27

Step-by-step explanation:

(x-3)(x-9)=x^2-3x-9x+27=x^2-12x+27

4 0
3 years ago
What is the formula for elimintation
inysia [295]

Answer:

The elimination method for solving systems of linear equations uses the addition property of equality. You can add the same value to each side of an equation. So if you have a system: x – 6 = −6 and x + y = 8, you can add x + y to the left side of the first equation and add 8 to the right side of the equation.

3 0
2 years ago
Read 2 more answers
A bacteria culture starts with 400 bacteria and grows at a rate proportional to its size. After 4 hours, there are 9000 bacteria
Kaylis [27]

Answer:

A) The expression for the number of bacteria is P(t) = 400e^{0.7783t}.

B) After 5 hours there will be 19593 bacteria.

C) After 5.55 hours the population of bacteria will reach 30000.

Step-by-step explanation:

A) Here we have a problem with differential equations. Recall that we can interpret the rate of change of a magnitude as its derivative. So, as the rate change proportionally to the size of the population, we have

P' = kP

where P stands for the population of bacteria.

Writing P' as \frac{dP}{dt}, we get

\frac{dP}{dt} = kP.

Notice that this is a separable equation, so

\frac{dP}{P} = kdt.

Then, integrating in both sides of the equality:

\int\frac{dP}{P} = \int kdt.

We have,

\ln P = kt+C.

Now, taking exponential

P(t) = Ce^{kt}.

The next step is to find the value for the constant C. We do this using the initial condition P(0)=400. Recall that this is the initial population of bacteria. So,

400 = P(0) = Ce^{k0}=C.

Hence, the expression becomes

P(t) = 400e^{kt}.

Now, we find the value for k. We are going to use that P(4)=9000. Notice that

9000 = 400e^{k4}.

Then,

\frac{90}{4} = e^{4k}.

Taking logarithm

\ln\frac{90}{4} = 4k, so \frac{1}{4}\ln\frac{90}{4} = k.

So, k=0.7783788273, and approximating to the fourth decimal place we can take k=0.7783. Hence,

P(t) = 400e^{0.7783t}.

B) To find the number of bacteria after 5 hours, we only need to evaluate the expression we have obtained in the previous exercise:

P(5) =400e^{0.7783*5} = 19593.723 \approx 19593.  

C) In this case we want to do the reverse operation: we want to find the value of t such that

30000 = 400e^{0.7783t}.

This expression is equivalent to

75 = e^{0.7783t}.

Now, taking logarithm we have

\ln 75 = 0.7783t.

Finally,

t = \frac{\ln 75}{0.7783} \approx 5.55.

So, after 5.55 hours the population of bacteria will reach 30000.

6 0
3 years ago
Adding fractions with unlike denominators<br>​
insens350 [35]

Answer:

A

Step-by-step explanation:

6 0
2 years ago
Read 2 more answers
What is 392,153 rounded to the nearest ten thousand
Alchen [17]

Step-by-step explanation:

392,153 rounded to the nearest ten thousand is 390,000

3 0
2 years ago
Read 2 more answers
Other questions:
  • Simplify the product by using FOIL <br><br> (6x-5)(2x-3)
    11·1 answer
  • PLZ HELP. THIS IS EASY PROBABLY HAHA. WILL GIVE THANKS AND BRAINLIEST
    14·2 answers
  • Use ΔPQR below to answer the question that follows: Which fact is not used to prove that PQR is similar to STR? (5 points) Segme
    13·2 answers
  • What is the area of the object above?
    15·2 answers
  • Which property is used to remove parentheses in mathematical expressions and equations?
    14·1 answer
  • The<br> square<br> root of<br> 80
    12·1 answer
  • Factorise 5x + 10=<br><br> ᴘʟᴀʏɪɴɢ: Who Asked (Feat: Nobody did ) ───────────⚪────── ◄◄⠀▐▐⠀►:/:⠀───○
    15·2 answers
  • Question Which of these strategies would eliminate a variable in the system of equations? 2x - y = 11 5x + 3y = -11 How many pos
    7·1 answer
  • What part of 72 is 2?
    15·2 answers
  • Use the figure to decide the type of angle pair that describes ∠5 and ∠2.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!