A freshly isolatedsample of 90Y was found to have an activity of 8.9 x 105 disintegrations per minute at 1:00pm on December 3, 2003. At 2:15pm on Dec, 17, 2003, its activity was redetermined and found to be 2.6 x 104 disintegrations per minute. Calculate the half-life of 90Y.

Answer:

Jeffery because the other dude go the 2 numbers wrong (he put the x coordinates on y and y on x)

Answer:

D 34

Step-by-step explanation:

i hope you understand

Complete Question

A two-state system is in an environment at temperature 500 K. The energy of state 1 is[tex]E_1=4.1e-20 J[/tex], and the energy of state 2 is [tex]E_2= 5.7e-20 J[/tex]. Let P(1) be the probability of finding the system in state 1, and be the probability of finding the system in state 2. What is the ratio P(2)/P(1)

Answer:

 [tex]X=0.0984[/tex]

Step-by-step explanation:

From the question we are told that:

Temperature T=500 K

Energy of state 1 [tex]E_1=4.1e-20 J[/tex],

Energy of state 2 is [tex]E_2= 5.7e-20 J[/tex]

Generally the equation for Probability of finding the system in state is mathematically given by

 [tex]P(1)=e ^{\frac{-E_1}{KT}}[/tex]

Therefore

For Probability of finding the system in state 1 [tex]P(1)[/tex]

 [tex]P(1)=e ^{\frac{-E_1}{KT}}[/tex]

Where

   K is Boltzmann constant

   [tex]K=1.38*10^{-23}[/tex]

 [tex]P(1)=e ^{\frac{-(4.1e-20 J)}{1.38*10^{-23}*500}}[/tex]

For Probability of finding the system in state 1 [tex]P(2)[/tex]

 [tex]P(2)=e ^{\frac{-(5.7e-20 J)}{1.38*10^{-23}*500}}[/tex]

Generally the equation for The Ratio of [tex]P(2)[/tex] and [tex]P(2)[/tex] is mathematically given by

 [tex]X=\frac{P(2)}{p(1)}[/tex]

 [tex]X=e ^{\frac{E_1-E_2}{KT}}[/tex]

 [tex]X=e ^{\frac{-(4.1-5.7)e-20 J)}{1.38*10^{-23}*500}}[/tex]

 [tex]X=0.0984[/tex]

Answer:

20 × 9= 180

...............................

Hi there!

[tex]\large\boxed{180 u^2}[/tex]

Use the following formula to solve for the area:

A = b × h

Plug in the given numbers:

A = 20 ×  9 = 180 units²

Answer:

More than half of the players are under age

40.

Step-by-step explanation:

Evaluating the expression : More than half of the players are under age 40.

Below 40s :

Number of players in 20s = 19

Number of players in 30s = 24

(19 + 24) = 43 players

40s and above :

40s = 8 players

50s = 10 players

60s = 5 players

70s = 2 players

(8 + 10 + 5 + 2) = 25 players

Hence, total number of players below 30s is more Than half of the total players

Answer:

C. The number of hours she babysits

Step-by-step explanation:

In this situation, the number of hours she babysits is the independent variable.

This is because it will directly influence the amount of money that she earns, which is the dependent variable.

For example, working for 1 hour will earn her $15.

So, the correct answer is C. The number of hours she babysits

Answer:

[tex]154m^{2}[/tex]

Step-by-step explanation:

8 · 7 = 56m (horizontal rectangle shape) the width was given by subtracting the total of the width (23m) minus (16m).

5 · 8 = 40m (square shape) Subtract 8m - 3m = 5m.

6 · 8 = 48m (square shape to the left of the polygon)

2 · 5 = 10m  (small rectangle shape bottom left) 8 - 6 = 2 for the length and 5 for the width by 8 - 3 = 5

56m + 40m + 48m + 10m = 154 [tex]m^{2}[/tex]

Answer: Maybe a

Step-by-step explanation:

I mean it is confusing but still look over it

Answer:

The bottom one looks correct

Step-by-step explanation:

Any number from 1-infinity will make that true

Answer:

the probability that they are assigned adjacent cubicles is  1 ÷ 4

Step-by-step explanation:

Given that

There is 8 new graduates are hired

2 of the graduates are bill and cathy

And, each one is assigned on random basis

We need to find out the probability

So,

= (2) (7!) ÷ (8!)

= (2) ÷ (8)

= 1 ÷ 4

Hence, the probability that they are assigned adjacent cubicles is  1 ÷ 4

The same would be relevant

Answer:

2,144.66 miles³

Step-by-step explanation:

v = (4/3)πr³

v = (4/3)π(8³)

v = 2,144.6605848506

Rounded

2,144.66 miles³

Answer:

c

Step-by-step explanation:

Answer:

C

Step-by-step explanation:

Solution :

From the table,

Number of countries = [tex]$N_i$[/tex]

Mean = [tex]$\overline Y_i$[/tex]

Standard deviation = [tex]$\sigma_i$[/tex]

Margin of error of B = 50,000 acres

So we determine the [tex]$\text{sample size n}$[/tex] and then allocate the four regions of [tex]$n_1, n_2, n_3$[/tex] and [tex]$n_4$[/tex].

Under the [tex]$\text{proportional allocation}$[/tex], the [tex]$\text{equation}$[/tex] for the value of [tex]$n_1$[/tex] which yields [tex]$V(\overline Y_{st}) = D = \frac{B^2}{H}$[/tex]  is given by :

[tex]$n=\frac{\sum_{K=1}^L N_K \sigma^2_K}{ND+\frac{1}{N}\sum_{K=1}^L N_K \sigma^2_K}$[/tex]

Let us complete the numerator

[tex]$\sum_{K=1}^L N_K \sigma^2_K = N_1\sigma_1^2 + N_2\sigma_2^2 + N_3\sigma_3^2 + N_4\sigma_4^2$[/tex]

                [tex]$= 1052 \times (271)^2 + 210 \times (79)^2 + 1376 \times (244)^2 + 418 \times (837)^2 $[/tex]

                = 453329920

The bound on the error of estimation is B = 50,000 acres

Hence we get

[tex]$D=\frac{B^2}{H}$[/tex]

  [tex]$=\frac{50000^2}{4}$[/tex]

  = 625,000,000

[tex]$n=\frac{\sum_{K=1}^L N_K \sigma^2_K}{ND+\frac{1}{N}\sum_{K=1}^L N_K \sigma^2_K}$[/tex]

  [tex]$=\frac{453329920}{3056 \times 625 + \frac{1}{3056} \times 453329920}$[/tex]

 = 220.24044

≈ 221 (approximately)

Therefore, the sample size under the proportional allocation from each stratum are given by :

[tex]$n_1=n\left[\frac{N_1}{\sum_{K=1}^\mu N_K}\right]$[/tex]

   [tex]$=221\left[\frac{1052}{3056}\right]$[/tex]

   ≈ 76

[tex]$n_2=n\left[\frac{N_2}{\sum_{K=1}^\mu N_K}\right]$[/tex]

   [tex]$=221\left[\frac{210}{3056}\right]$[/tex]

   ≈ 15

[tex]$n_3=n\left[\frac{N_3}{\sum_{K=1}^\mu N_K}\right]$[/tex]

   [tex]$=221\left[\frac{1376}{3056}\right]$[/tex]

   ≈ 100

[tex]$n_4=n\left[\frac{N_4}{\sum_{K=1}^\mu N_K}\right]$[/tex]

   [tex]$=221\left[\frac{418}{3056}\right]$[/tex]

   ≈ 30

Thus, we should select 76 counties from North central region, 15 counties from the north east region, 100 from south region and 30 from west region.

We can also estimate mean acreage of each county across all the county with a margin of error of 50,000 acres.

Answer:

[tex]\frac{a^2 + b^2 +c ^2}{a*b + a*c + b*c} = -2[/tex]

Step-by-step explanation:

if:

a + b + c = 0

then we can rewrite:

c = -a - b

Now we can replace this in our expression:

[tex]\frac{a^2 + b^2 + c^2}{a*b + a*c + b*c} = \frac{a^2 + b^2 + (-a - b)^2}{a*b + a*(-a - b) + b*(-a - c)}[/tex]

Now we can rewrite:

(-a - b)^2 = a^2 + 2*a*b + b^2

Then we can rewrite our expression as:

[tex]\frac{a^2 + b^2 + a^2 + b^2 + 2*a*b}{a*b - a^2 - a*b - b^2 - b*a}[/tex]

Let's keep simplifying this:

[tex]\frac{2*(a^2 + b^2 + a*b)}{-a*b - b^2 - a^2}[/tex]

Here is easy to see the simplification we need to do, as we have the same factor in the denominator as in the numerator (just a different of sign).

[tex]\frac{2*(a^2 + b^2 + a*b)}{-a*b - b^2 - a^2} = \frac{2*(a^2 + b^2 + a*b)}{-(a^2 + b^2 + a*b)} = -2[/tex]

Then the expression is equal to -2

[tex]\frac{a^2 + b^2 +c ^2}{a*b + a*c + b*c} = -2[/tex]

Answer:

aaaaa

Step-by-step explanation:

Answer:

I think it’s A

Step-by-step explanation:

Answer:

[tex]y = 10x[/tex]

Step-by-step explanation:

Given

The attached plot

Required

The line of the best fit using [tex](8,80)[/tex] and [tex](2,20)[/tex]

We have:

[tex](x_1,y_1) = (8,80)[/tex]

[tex](x_2,y_2) = (2,20)[/tex]

Calculate slope (m)

[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]

[tex]m = \frac{20 - 80}{2- 8}[/tex]

[tex]m = \frac{-60}{-6}[/tex]

[tex]m = 10[/tex]

The equation is then calculated using:

[tex]y = m(x - x_1) + y_1[/tex]

[tex]y = 10(x - 8) + 80[/tex]

Expand

[tex]y = 10x - 80 + 80[/tex]

[tex]y = 10x[/tex]

Answer:

How many thirds are equal to 2/6?

1/3 = 1/3

2/6 = 1/3

3/9 = 1/3

4/12 = 1/3

Step-by-step explanation:

I hope that this answer helps you to understand your question more thoroughly. If you have any other questions, please put them below.  

Have a great rest of your day/night!

1 thirds

divide 2/6 by 2 and you get 1/3. or multiply 1/3 by two and you get 2/6.

Answer: hello! have a good day! :)))

P = 2

Well the answer is 3,375

Answer:

Step-by-step explanation:

-4<n≤5

(a) 67900

(b) 291700

(a) 25 x 679 x 4

Rearrange the terms starting with the smallest

4 x 25 x 679

The property used here is the commutative property of multiplication which states that the order in which these numbers are multiplied does not matter.

Now solve

4 x 25 x 679 = 67900

(b) 2917 x 102 - 2917 x 2

Factor out the common terms

2917(102 - 2)

Using the distributive property which states that when a number is multiplied by the sum or difference of two numbers, the result is the same as multiplying each of the two numbers by the number and then adding or subtracting the products.

Now solve

2917(102 - 2) = 2917(100)

= 291700

Answer:

11+y > -33

Step-by-step explanation:

Answer:

You wrote

"Which of the following" Meaning there's should be options present.

But Going with the statement...

The sum of 11 and y is greater than -33

I'd say

11 + y > -33.

Answer:

3.333 hours

Step-by-step explanation:

Given the total distance is 30 miles, and boat 1 travels at 3 mph and boat 2 travels at 6 mph, and the time for both is the same. Distance is speed S times time T so

30 = D(boat 1) + D(boat 2)

30 = (S1 * T) + (S2 * T)

30 = 3T + 6T

30 = 9T

3.333 = T

Answer:

12

Step-by-step explanation:

y = 3 so

4 × 3 = 12

The value of 4y at y=3 is 12.

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides. LHS = RHS is a common mathematical formula.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given:

Expression : 4y

Now, we have to put y= 3

So, 4y

= 4(3)

= 12

Hence, the value of 4y at y=3 is 12

Learn more about Equation here:

https://brainly.com/question/10413253

#SPJ2

Answer:

[tex]v=<\sqrt{32}cos(319.11^{\circ}),\sqrt{32}sin(319.11^{\circ})>[/tex] or [tex]v=\sqrt{32}cos(319.11^{\circ})i+\sqrt{32}sin(319.11^{\circ})j[/tex]

Step-by-step explanation:

Find the magnitude of [tex]<2\sqrt{6},-2\sqrt{2}>[/tex]:

[tex]||v||=\sqrt{(2\sqrt{6})^2+(-2\sqrt{2})^2}[/tex]

[tex]||v||=\sqrt{24+8}[/tex]

[tex]||v||=\sqrt{32}[/tex]

Find the direction angle of [tex]<2\sqrt{6},-2\sqrt{2}>[/tex]:

[tex]\alpha=tan^{-1}|\frac{-2\sqrt{2}}{2\sqrt{6}}|[/tex]

[tex]\alpha=tan^{-1}|-\frac{\sqrt{3}}{2}|[/tex]

[tex]\alpha=tan^{-1}(\frac{\sqrt{3}}{2})[/tex]

[tex]\alpha=40.89^{\circ}[/tex]

Since [tex]\alpha=40.89^{\circ}[/tex] is our reference angle, we determine our direction angle [tex]\theta[/tex] by verifying our angle is in Quadrant IV, which is where the vector is located. Therefore, [tex]\theta=360^{\circ}-\alpha=360^{\circ}-40.89^{\circ}=319.11^{\circ}[/tex]

To represent a vector's magnitude and direction in trigonometric form, we use the form [tex]v=<||v||cos\theta,||v||sin\theta>[/tex] or [tex]v=||v||cos\theta i+||v||sin\theta j[/tex].

In conclusion, the trigonometric form of the vector is:

[tex]v=<\sqrt{32}cos(319.11^{\circ}),\sqrt{32}sin(319.11^{\circ})>[/tex] or

[tex]v=\sqrt{32}cos(319.11^{\circ})i+\sqrt{32}sin(319.11^{\circ})j[/tex]

Answer:

7 socks were sold

Step-by-step explanation:

7*8=56

11-7=4

4×11=44

56+44=100

This proves the answer of 7 to be correct

Multipuly po ba (15;000 7%)

Answer:

23

Step-by-step explanation: