Answers
Related Questions
Rachel has an unknown sample of a radioisotope listed in the table. Using a special technique, she is able to measure the mass of just the unknown isotope as 104. 8 kg at 12:02:00 P. M. At 4:11:00 P. M. On the same day, the mass of the unknown radioisotope is 13. 1 kg. Which radioisotope is in the sample? Potassium-42 Nitrogen-13 Barium-139 Radon-220.
Answers
The radioactive isotopes of an element are known as radioisotopes. The radioisotope sample that is given is Barium-139.
What is radioisotope?The radioactive isotopes of an element are known as radioisotopes. Atoms with an unstable mix of neutrons and protons, or excess energy in their nucleus, are also known as neutron-proton atoms.
As it is given that the initial mass of the sample at 12:02:00 PM is,
[tex]m_1=104.8\ kg[/tex]
The Mass of the sample at 4:11:00 PM is given as
[tex]m_2 = 13.1 kg[/tex]
So here since it is a sample of radioactive isotope so here we will say
[tex]m_2=m_1e^{-\lambda t}[/tex]
Now from the above data, we know that the time taken to reduce the mass is
[tex]\rm t = 4\ hours\ 9\ minutes = 4.15\ hours[/tex]
Further, from the above equation, we will have
[tex]13.1 =104.8 e^{-\lambda(4.15)}\\\\\lambda(4.15)=2.08\\\\\lambda = 0.50/ hour[/tex]
So here half-life is given as
[tex]\rm T_{\frac12}=\dfrac{ln2}{\lambda}\\\\ T_{\frac12} = 1.4\ hours[/tex]
Thus, here this isotope must be the one that will have a half-life of 1.4 hours
Therefore, it is nearly Barium-139.
Hence, the radioisotope sample that is given is Barium-139.
Learn more about Radioisotope:
https://brainly.com/question/49002
this is what i see :)
Answers
Answer:
it is 7/34
Step-by-step explanation:
The Median is 1 squared
I need help lollllllllll
Answers
Answer:
the points: T(-6,-8) U(-1,-4) V(0,7) W(5,5) X(-7,3) Y(2,5) Z(6,0)
Hope this helps!
julia’s dad bought a car for $15,000. the purchase price was seven-eighths of its retail price.
what is the decimal value of the discount given to julia’s father by the car dealership?
Answers
Answer: 0.125
Step-by-step explanation: Trust me
Snap ~ daddy_shadet
Which inequality represents this sentence? Seven times four is greater than or equal to eight times three.
A. 7 • 4 ≥ 8 • 3
B. 7 • 4 ≤ 8 • 3
C. 7 • 4 < 8 • 3
D. 7 • 4 > 8 • 3
Answers
Step-by-step explanation:
Answer B
7 × 4=28
8×3=24
Thank me later
What is the percent of decrease from 84 to 21
Answers
Answer:
84 decreased to 21 is 25%
Part B
Describe two different ways you could find measure of ZCFD. What is the measure of
this angle? There are three parts to this question.
Answers
Answer:
b
Step-by-step explanation:
you aint got enough information
Gabby has entered a cooking contest with 6 rounds. In order to earn a medal, she needs a final average score higher than 75. After the first five rounds, her average score is 78. What must her score be in the sixth (final) round to earn a medal? Show your work and answer in a complete sentence.
Answers
Answer:
85
Step-by-step explanation:
We will use the formula
xbar = \sum Xi/N
xbar is the average
N is the number of rounds
\sum Xi is sum of rounds
From the formula:
\sumXi = xbar × N.
If Gabby has entered a cooking contest with 6 rounds and in order to earn a medal, she needs a final average score higher than 75, this means that;
N = 6
xbar = 75+x (since her average needs to be more than 75)
Substitute in the formula
\sumXi = 6(75+x) ....... 1
If after the first five rounds, her average score is 78, then:
At N = 5, xbar = 78
Substitute into the formula
\sumXi = 5(78)
\sumXi = 390..... 2
First we need to get x by equating equation 1 and 2:
6(75+x) = 390
450 + 6x = 390
6x = 390-450
6x = -60
x = -10
Taking x as 10
Since she needs 75+x to earn the medal, substitute x = 10 into the expression:
This means that she will need average score of 75+10 i.e 85 to win the medal
you got a bunch of apples. one third is rotten, one fourth is ripe. How much is left?
Answers
Answer:5/12
Step-by-step explanation:
1/3=4/12
1/4=3/12
=7/12
12/12-7/12=5/12
One third of 12 =1/3 *12/1
= 4
Therefore 4 apples are rotten
One fourth of 12 = 1/4 *12/1
= 3
Therefore 3 apples are ripe
Number of apples left =. 12- 3 +4
According to the DMAS rule we have to do Addition first ,so 3+4 = 7
Now we have to subtract 12-7 that will be 5
so therefore number of apples left = 5
Hope it helped you please mark as brainliest
I have no idea how to solve this
Answers
x = 25
Step-by-step explanation:Hi there !
the opposite angles are equal4x - 25 = 25 + 2x
4x - 2x = 25 + 25
2x = 50
x = 50 : 2
x = 25
Good luck !
Proportional Relationships
Solve for X
Answers
Answer:
x=9/6
Step-by-step explanation:
[tex] \frac{20}{16 } = \frac{12}{x} [/tex]
12×16=192
192÷20=9.6
Help please!!!!!!!!!!!!
Answers
Answer:
The answer is 13
Step-by-step explanation:
ABC is equal to GHI, so AB = GH which is 13
QUICK! Use long dvision to find a repeated decimal equlvalency for the fraction. Include all of your work as part of your final answer. 8/9
Answers
Answer:
.8888888889
Step-by-step explanation:
caculator
Pls can someone give me the answers
Answers
Step-by-step explanation:
1.
x=5
y=4
2.x=4.2
y=19.8
3. x=16
y=70.4
4. a=28
b=25/7
5.a=20
b=18
6. a=51
b=75
7. x=30
y=21
8.a=27
b=6
hope it helps:)
ignore that fig '-'
Answer:k
Step-by-step explanation:
What is the value of x ?
5.5
9
11.5
13
Answers
Answer:
itz 5.5
Step-by-step explanation:
i just got it right
Archimedes was not the first to solve the problem. Descartes was neither the first nor the last to finish. Hypatia completed the puzzle immediately after Archimedes. Euler wasn’t the second student to complete the puzzle. Gauss completed the puzzle two students after Euler. In what order did the students complete the puzzle?
Answers
Answer:
Euler, Descartes, Gauss, Archimedes, Hypatia
Step-by-step explanation:
I just used a logic puzzle format thing so its rly hard to explain in words but I hope this helped and if you have any specific questions you can comment and ask! Also welcome to brainly if youre new (your question has the first question banner on it ) and also if you think my answer deserves brainliest i would really appreciate it! It would also be amazing if ppl would rate this answer so future users know if it's right!
PLZZZZ HELP! write the equation in standard form y=3/4x - 4
Answers
Answer:
3x-4y = 16
Step-by-step explanation:
2+4+2+ 6+4+5+4+6+3+2+2+1
Answers
Answer:
41
Step-by-step explanation:
2+4+2+ 6+4+5+4+6+3+2+2+1= 41
plz mark brainleist
[tex]\huge\boxed{41.}[/tex]
Given...
[tex]2+4+2+ 6+4+5+4+6+3+2+2+1=\boxed{?}[/tex]
Solution...[tex]\left[\begin{array}{ccc}2+4=6\\6+2=8\\8+6=14\\14+4=18\\18+5=23\\23+4=27\\27+6=33\\33+3=36\\36+2=38\\38+2=40\\40+1=40\end{array}\right][/tex]
Final answer...[tex]\huge\boxed{41.}[/tex]
[tex]\boxed{-----------------------------------}[/tex]
[tex]\boxed{Hope\;i\;helped!}\\\\\\\\\huge\boxed{Thanks,Plip.}[/tex]
Need help? Contact me in the future! I am an expert verified Brainly user!Proof of expert verified... See below!brainly.com/question/18189573
brainly.com/question/18187934
brainly.com/question/18130122
brainly.com/question/15993626
brainly.com/question/949861
brainly.com/question/18169685
brainly.com/question/18409039
brainly.com/question/18407068
brainly.com/question/18681048
Which of the following expressions are equivalent to a x + y + z?
Answers
Answer:
A
Step-by-step explanation:
Addition Property of Equality
If two expressions are equal to each other, and you add the same value to both sides of the equation, the equation will remain equal.
Hope this helps! Please let me know if you need more help or think my answer is incorrect. Brainliest would be MUCH appreciated. Have a wonderful day!
Erica solved the equation −5x − 25 = 78; her work is shown below. Identify the error and where it was made. (5 points) −5x − 25 = 78 Step 1: −5x − 25 − 25 = 78 − 25 Step 2: −5x = 53 Step 3:negative five times x over negative five = fifty-three over negative five Step 4: x = negative fifty-three over five Group of answer choices Step 1: She should have added 25 to each side. Step 1: She should have divided both sides by −5. Step 3: She should have divided both sides by −5. Step 3: She should have multiplied both sides by −5.
Answers
Answer:
x = -20.6
Step-by-step explanation:
Step 1: −5x − 25 − 25 = 78 − 25
Should be
Step 1: -5x-25+25=78+25
Step 2: -5x=103
Step 3: Divide both sides by -5: x = -20.6
Answer:
Option A. Step 1: She should have added 25 to each side
Step-by-step explanation:
I got it right on my quiz :)
A triangular pane of glass has a height of 48 inches and an area of 576 square inches. What is the length of the base of the pane?
URGENT
Answers
Answer:
12
Step-by-step explanation:
Solution:
We know that:
Area of triangular pane = 576 in²Height of triangular pane = 48 inArea of triangle formula = 1/2 x Base x AltitudeSubstituting the height and the area of the pane in the formula
Area of triangle = 1/2 x Base x Altitude = 576 in²1/2 x Base x 48 = 576 in²Simplifying the LHS:
1/2 x Base x 48 = 576 in²Base x 24 = 576 in²Dividing 24 both sides
(Base x 24)/24 = 576/24Base = 576/24 = 24 inThus, the measure of the base is 24 inches.
what is addition property of equality
Answers
Answer:
Additive property of equality states that if we add or subtract the same number to both sides of an equation, the sides remain equal.
A conference will take place in a large hotel meeting room. The organizers of the conference have created a drawing for how to arrange the room. The scale indicates that 1/2 inch on the drawing corresponds to 12 feet in the actual room. In the scale drawing, the length of the room is 3 1/3 inches. What is the actual length of the room?
Answers
Answer:
The actual length of the room is 40 feet
Step-by-step explanation:
Given
[tex]Scale = \frac{1}{2}\ inch : 12\ feet[/tex]
Required
Determine the actual measurement of [tex]3\frac{1}{3}\ inches[/tex]
Represent the required actual measurement with x
i.e.
[tex]3\frac{1}{3}\ inches : x[/tex]
And we have:
[tex]\frac{1}{2}\ inch : 12\ feet[/tex]
[tex]3\frac{1}{3}\ inches : x[/tex]
Cross Multiply
[tex]x * \frac{1}{2} = 12 * 3\frac{1}{3}[/tex]
Convert fraction to improper fraction
[tex]x * \frac{1}{2} = 12 *\frac{10}{3}[/tex]
[tex]\frac{x}{2} = \frac{120}{3}[/tex]
[tex]\frac{x}{2} = 40[/tex]
Multiply both sides by 2
[tex]x = 40 * 2[/tex]
[tex]x = 80\ feet[/tex]
The actual length of the room is 40 feet
Select all the points that are on a line with a slope of 2 that also contains the point (2,-1)
A. (3,1)
B. (1,1)
C. (1,-3)
D. (4,0)
E. (6,7)
Answers
Answer:
A and C
Step-by-step explanation:
m = 1 - (-1) / 3-2 = 2/1 = 2
m = -3 - (-1) / 1 - 2 = -2/-1 = 2
Tan A=2. 0503 find each angle measure to the nearest degree
Answers
Answer: 26 degrees
Step-by-step explanation:
The value of a baseball card can be represented by the equation y = 3 x + 39, where x represents the number of years that Robert has owned the card and y represents the total value, in dollars, of the card. What was the value of the card when Robert originally purchased it?
$3
$13
$36
$39
Answers
Answer:
the answer should be $39
Answer:
d) 39
Step-by-step explanation:
What is 90% of 10
A:1
B:3
C:9
D:900
Answers
Answer:
C
Step-by-step explanation:
10*.9=9
the difference of n and 15 is less than or equal to 37
Answers
Answer: n ≤ 52
Step-by-step explanation:
less than or equal to is usually write as ≤.
n - 15 ≤ 37
+15 +15 [Add 15 to the both sides]
n ≤ 52
Write an equivalent expression for (x + 4)^2
distributive property
Answers
Answer:
x² + 8x + 16
Step-by-step explanation:
(x + 4)²
= (x + 4)(x + 4)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x + 4) + 4(x + 4) ← distribute parenthesis
= x² + 4x + 4x + 16 ← collect like terms
= x² + 8x + 16
TRIGONOMETRY QUESTION
Can someone please explain to me on how to find out the angle using trigonometry. I also think you have to use SOH but I’m unsure. Can someone tell me how to find a)