Answer:
not sure what you need but I would be happy to help
the half life of c14 is 5730 years. Suppose that wood found at an archeological excavation site contains about 35% as much C14 as does living plant material. Determine when the wood was cut
Answer:
The wood was cut approximately 8679 years ago.
Step-by-step explanation:
At first we assume that examination occured in 2020. The decay of radioactive isotopes are represented by the following ordinary differential equation:
[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)
Where:
[tex]\frac{dm}{dt}[/tex] - First derivative of mass in time, measured in miligrams per year.
[tex]\tau[/tex] - Time constant, measured in years.
[tex]m[/tex] - Mass of the radioactive isotope, measured in miligrams.
Now we obtain the solution of this differential equation:
[tex]\int {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]
[tex]\ln m = -\frac{1}{\tau} + C[/tex]
[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)
Where:
[tex]m_{o}[/tex] - Initial mass of isotope, measured in miligrams.
[tex]t[/tex] - Time, measured in years.
And time is cleared within the equation:
[tex]t = -\tau \cdot \ln \left[\frac{m(t)}{m_{o}} \right][/tex]
Then, time constant can be found as a function of half-life:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)
If we know that [tex]t_{1/2} = 5730\,yr[/tex] and [tex]\frac{m(t)}{m_{o}} = 0.35[/tex], then:
[tex]\tau = \frac{5730\,yr}{\ln 2}[/tex]
[tex]\tau \approx 8266.643\,yr[/tex]
[tex]t = -(8266.643\,yr)\cdot \ln 0.35[/tex]
[tex]t \approx 8678.505\,yr[/tex]
The wood was cut approximately 8679 years ago.
Which expression is the coefficient of the n term -1
Answer:
C. -2n² - n + 5
Step-by-step explanation:
In expression C, the coefficient of the n term is -1;
The expression in choice C is given as:
-2n² - n + 5
The coefficient is the number before a variable;
For n², the coefficient is -2
for n, the coefficient is -1
In an attempt to improve brand recognition, the marketing department of AC Sports is
creating conical paper water cups with their brand printed around the surface of the
cup. The cups will be sent to athletic departments for free. About how much space do
the graphic artists working on the design have to work with if the cup will have a
diameter of 2.5 inches and a height of 3.5 inches?
Answer:
about 37.31 inches of space
Step-by-step explanation:
In this case, you would need to find the area of a cylinder with these dimensions.
Formula: 2πrh+2πr²
The r is the radius, and since the diameter in this situation would be 2.5, the radius would be 1.25.
2π(1.25)(3.5)+2π(1.25)²
2π4.375+2π1.5625
8.75π+3.125π
37.3064128
about 37.31 inches of space
QUICK
solve this equation
a^n+b^n=
Simplify (-4/5)divided by (3/-2). -8/15 -6/5 6/5 8/15
Answer:
8/15
Step-by-step explanation:
-4/5 ÷ -3/2
Copy dot flip
-4/5 * -2/3
Multiply the numerators
8
Multiply the denominators
15
Put the numerator over the denominator
8/15
Answer: 8/15
Step-by-step explanation: (-4/5)divided by (3/-2) is 8/15.
Number 10 plzz???????
rewrite the equation 10=1,000 with an exponet that makes it true .
Answer:
[tex]10^3=1,000[/tex]
Step-by-step explanation:
The expression 10=1,000 is obviously false, but we can make it true by rewriting it with an exponent.
Note that 1,000=10*10*10
Or, equivalently:
[tex]1,000=10^3[/tex]
Thus, if we modify the original false expression and add an exponent 3 to the base 10, then it would be true:
Original:
10=1,000 => false
Rewritten true:
[tex]\boxed{10^3=1,000}[/tex]
what is the answer for 14x divided by 7x
Answer:
2x
Step-by-step explanation:
You're dividing 14 multiplied by a number by 7 multiplied by a number. So you'd get 2 multiplied by a number.
Calculate.
(2x105)(4.3x109)
Write your answer in scientific notation.
Answer:
9.8427x10⁴
Step-by-step explanation:
Answer:
98427x^2
9.8427x10^4
Step-by-step explanation:
What number must be added to 101 to produce a number equal to the product of 101 x 21
Answer:
2020
Step-by-step explanation:
101 • 21 = 2121
2121 - 101 = 2020
anyone in flvs? we should find each other in live lessons lol
Answer:
nope
Step-by-step explanation:
-4 (2x + 13) + 3x = 80
How do you solve this out and get the answer
Answer:
-132/5
Step-by-step explanation:
-4(2x+13) + 3x = 80
-8x - 52 + 3x = 80
-5x = 80+52
5x = -132
x = -132/5
Feel free to mark this as brainliest! :D
Two people start walking at the same time in the same direction. One person walks at 8 mph and the other
person walks at 3 mph. In how many hours will they be 1.25 miles apart?
Answer:
0.25hoursStep-by-step explanation:
Data
speed v1=8mph
speed v2=3mph
distance= 1.25
time t=?
speed= distance/time
distance=speed*time
1.25=8*t-3*t
1.25=8t-3t
1.25=5t
t=1.25/5
t=0.25hours
In minutes it is 15min
In a certain state's lottery, 45 balls numbered 1 through 45 are placed in a machine and eight of them are drawn at random. If the eight numbers drawn match the numbers that a player had chosen, the player wins $1,000,000. In this lottery, the order in which the numbers are drawn does not matter.
Compute the probability that you win the million-dollar prize if you purchase a single lottery ticket. Write your answer as a reduced fraction.
P
(win) =
A single lottery ticket costs $2. Compute the Expected Value, to the state, if 10,000 lottery tickets are sold. Round your answer to the nearest dollar.
Answer: $
A single lottery ticket costs $2. Compute the Expected Value, to you, if you purchase 10,000 lottery tickets. Round your answer to the nearest dollar.
Answer: $
Step-by-step explanation:
The order of the numbers doesn't matter, so we'll use combinations instead of permutations. The number of combinations is:
₄₅C₈ = 215,553,195
So the probability of a ticket having the winning combination is 1 / 215,553,195.
The expected value to the state is:
E(X) = 10,000 (1) ($2) + 10,000 (1 / 215,553,195) (-$1,000,000)
E(X) = $19954
The expected value to you is:
E(X) = 10,000 (1) (-$2) + 10,000 (1 / 215,553,195) ($1,000,000)
E(X) = -$19954
what is 8 times 0.9 equal
Answer:
7.2
Step-by-step explanation:
What is the measure of an exterior angle of a regular 14-sided polygon? Enter your answer as a decimal in the box. Round to the nearest tenth of a degree.
Answer:
21.715 degrees.
Step-by-step explanation:
There are 14 vertexes (vertices) for a 14-gon. It is 'regular' so all these angles are equal. So the exterior angle of each is 180-154.285 = 21.715 degrees.
Whats 27.16 - 3.1 x 1.4 evaluated?
PLEASE HELP
Answer:
22.82
Step-by-step explanation:
can u plz mark me as brainliest??
Answer:
22.82
Step-by-step explanation:
3.1*1.4 = 4.34
27.16-4.34 = 22.82
[edited, I messed up the order of operations before, sorry]
Perform the indicated operation
3/4 divided by 1/3
Answer:
2 1/4
Step-by-step explanation:
3/4 ÷ 1/3 = ?
(to divide fractions faster you flip the second fraction so:)
3/4 x 3/1 = 2 1/4
Write an equation in the line in slope intercept form
Answer:
Y=2x-1
Step-by-step explanation:
In order to find the slope, its rise over run. So you would move from (0,-1) to the next point it intercepts, (1,1) and find it from there
As for the Y-Intercept, it would just be wherever the line connects with the Y axis, which happens to be (0,-1) or Negative 1.
Need help i will mark you brainliest
Willa Schaefer deposited $3,000 in a savings plan with her credit union. The credit union savings plan pays 3% interest compounded semiannually. If she makes no other deposits or withdrawals: what is the amount in the account after 2 1/2years?
Answer:
225776
Step-by-step explanation:
Trust me i got it right.
Your teacher invented another game: You will pick one card from a deck of cards. If
you pick a heart, you will win $25.00. Otherwise, you will lose $5.00.
From the standpoint of the player, what is the expected value of this game?
Enter expected value
What does the expected value tell us about the game?
O The game is good to play, you will make money on average.
O The game is NOT good to play, you will tend to lose money.
O It doesn't matter if you play, you will generally break even.
Answer:
C
Step-by-step explanation:
7th grade math help me plzzzz
Answer:
a. -14
b. -13
c. -5
d. -3
e. -12
f. 0
Step-by-step explanation:
hope it helps
Answer:
A is -14.
B is -13
C is -5
D is -3
E is -12
F is 0
Step-by-step explanation:
A, B, E both numbers are negative so you just add them together and add a negative sign.
C would read 4-9
D 10-7 and add a - to the answer
F is 6-6
70 + x + 55 + 30 = 180
Answer:
x=25
Step-by-step explanation:
First, we add all like terms. Then, we solve for x.
[tex]70+x + 55 + 30 = 180\\x+70 + 55 + 30 = 180\\x+155=180\\x=25[/tex]
We can rearrange some things because order does not matter with addition. Next, we just use basic equation solving techniques.
Answer:
25. Hope this helps :)
Step-by-step explanation:
180-70=110
110-55=55
55-30=25
Your missing answer would be 25
X=25
Blood pressure: High blood pressure has been identified as a risk factor for heart attacks and strokes. The proportion of U.S. adults with high blood pressure is 0.4. A sample of 39 U.S. adults is chosen. Use the TI-84 Plus Calculator as needed. Round the answer to at least four decimal places. Part: 0 / 60 of 6 Parts Complete Part 1 of 6 Is it appropriate to use the normal approximation to find the probability that more than 43% of the people in the sample have high blood pressure? It ▼(Choose one) appropriate to use the normal curve, since =np ▼(Choose one)10 and =n−1p ▼(Choose one) 10.
Answer:
Yes it appropriate to use the normal approximation to find the probability that more than 43% of the people in the sample have high blood pressure
Step-by-step explanation:
From the question we are told that
The population proportion is p=0.4
The sample size is n = 39
The sample proportion is [tex]\^ p = 0.43[/tex]
Generally for normal approximation to be used
[tex]np > 10[/tex]
so np = 39 * 0.4 = 15.6 > 10
and [tex]n(1- p) > 10[/tex]
so n(1-p ) = 39(1-0.4) = 23.4 >10
Given that the both condition is meet it mean that it appropriate to use the normal approximation to find the probability that more than 43% of the people in the sample have high blood pressure
When five times a number is decreased by 9, the result is 11. What is the number?
Answer
4
Step-by-step explanation:
Add 9 to 11, then divide that by 5.
Answer:
4
Step-by-step explanation:
work backwards 11+9 is 20. Divide 20 by 5 = 4
Which ordered pair, if included in this relation, would cause it to no
longer be a function?
Answer:
(-6,3)
Step-by-step explanation:
Julie bought 3 tomatoes for a price of $0.60 each. Using the key, create a
model to represent how much Julie can expect to pay for the tomatoes.
Then write an equation that matches your model.
KEY
- 1 dollar
Answer:
y=.60x
Step-by-step explanation:
where y is the amount of money Julie can expect to pay
where x is the amount of tomatoes she is buying
i dont understand what the key means, but this would be the appropriate model for this problem
Can i get brainliest please?
X+ 2 = 5 and y-3 = 2
Answer:
x=3
y=5
because 5-2=3 so 3 is x
and 2+3 is 5 so y is 5
Answer:
X = 3, Y =
Step-by-step explanation:
This is because 2+3=5,
and5-3=2
I need help nowwwwww !!!!!????
you should just have to times the yards by three like the second one is 12