The half-life of radioactive radium (226Ra) is 1599 years. What percent of a present amount of radioactive radium will remain after 275 years?

Answers

Answer 1

Answer:

88.76%

Step-by-step explanation:

Given that :

Half life of radium = 1599 years

Percentage that will remain after 275 years

Using the relation :

y = Ae^kt

Where ; A = mass of radium and t = half life = 1599, A = initial mass

By 1599, the mass of radium will be half its initial

Hence,

y = initial / 2 = A /2

A/2 = Ae^kt

To obtain the value of k

0.5 = e^1599k

In0.5 = 1599k

k = (In0.5)/1599

k = - 0.0004335

Hence,

y = Ae^-0.0004335t

Amount of radium. After 275 years : t = 275

y = Ae^-0.0004335*275

y = A0.8876191

y = 0.8876191 of intial amount

Hence, 0.8876191 * 100%

= 88.76%


Related Questions

Find the equation of a line that has a slope of -3/7 and goes through the point (49,-17)

Answers

It should be

Y = -3/7x + 4

___ x 2 = 30

12 divided by ___ = 4

Just a practice :)

Answers

Answer:
15 x 2= 30

12/3=4

15 x 2 = 30

12 ÷ 3 = 4

Have a wonderful day!

- Audrey :)

Natalie drove 12.25 hour for a total of 686 miles. How fast did she drive in miles per hour?​

Answers

Answer:

step 1= 12.25*60=735minutes

step 2=686/735=0.933333kilometer.

step 3=0.9333333*60=56kilometers.

When is subtraction always the first operation done in an expression?

Answers

Answer:

When it is in parentheses.

Step-by-step explanation:

In PEMDAS, first is always parentheses, no matter what operation.

If it is subtraction, do that first.

hope this helped!

Answer:

the 3rd one

Step-by-step explanation:

this is only true when it is in perenthisis because when you do PEDMAS you go in that order. P (perenthisis) beng first. so TECHNECLY perenthisis is first, but the first actual MATH PROBLEM being done is subtraction.

Find the area of a compound shape

Can you please explain

Answers

Answer:

Bruh the answer is there so uh yea

Step-by-step explanation:bruh sorry for being a little rude.

a tank containing 50 liter of water develops a leak and loss water at a constant rate. after 20 minutes it contains 40 liter. after a further 30 minutes the tank is 5% of its full capacity. determine the tanks capacity

Answers

Answer:

The tank's capacity is 500 liters

Step-by-step explanation:

Proportions

The tank initially contains 50 liters of water. The tank's capacity is more than that, as we'll show later.

We know after 20 minutes of leaking from the tank, 40 liters still remain. This means 10 liters have leaked in 20 minutes. The loss of water occurs at a constant rate or 10/20=0.5 liters per minute.

After 30 more minutes, the tank has lost 0.5*30 = 15 more liters of water and now has 40 - 15 = 25 liters remaining.

We are told those 25 liters correspond to 5% of the tank's full capacity. Thus, the full capacity of the tank is:

[tex]\displaystyle \frac{25 }{ (5 / 100)} = 500~liters[/tex]

The tank's capacity is 500 liters

(x +y)^5
Complete the polynomial operation

Answers

Answer:

Please check the explanation!

Step-by-step explanation:

Given the polynomial

[tex]\left(x+y\right)^5[/tex]

[tex]\mathrm{Apply\:binomial\:theorem}:\quad \left(a+b\right)^n=\sum _{i=0}^n\binom{n}{i}a^{\left(n-i\right)}b^i[/tex]

[tex]a=x,\:\:b=y[/tex]

[tex]=\sum _{i=0}^5\binom{5}{i}x^{\left(5-i\right)}y^i[/tex]

so expanding summation

[tex]=\frac{5!}{0!\left(5-0\right)!}x^5y^0+\frac{5!}{1!\left(5-1\right)!}x^4y^1+\frac{5!}{2!\left(5-2\right)!}x^3y^2+\frac{5!}{3!\left(5-3\right)!}x^2y^3+\frac{5!}{4!\left(5-4\right)!}x^1y^4+\frac{5!}{5!\left(5-5\right)!}x^0y^5[/tex]

solving

[tex]\frac{5!}{0!\left(5-0\right)!}x^5y^0[/tex]

[tex]=1\cdot \frac{5!}{0!\left(5-0\right)!}x^5[/tex]

[tex]=1\cdot \:1\cdot \:x^5[/tex]

[tex]=x^5[/tex]

also solving

[tex]=\frac{5!}{1!\left(5-1\right)!}x^4y[/tex]

[tex]=\frac{5}{1!}x^4y[/tex]

[tex]=\frac{5}{1!}x^4y[/tex]

[tex]=\frac{5x^4y}{1}[/tex]

[tex]=\frac{5x^4y}{1}[/tex]

[tex]=5x^4y[/tex]

similarly, the result of the remaining terms can be solved such as

[tex]\frac{5!}{2!\left(5-2\right)!}x^3y^2=10x^3y^2[/tex]

[tex]\frac{5!}{3!\left(5-3\right)!}x^2y^3=10x^2y^3[/tex]

[tex]\frac{5!}{4!\left(5-4\right)!}x^1y^4=5xy^4[/tex]

[tex]\frac{5!}{5!\left(5-5\right)!}x^0y^5=y^5[/tex]

so substituting all the solved results in the expression

[tex]=\frac{5!}{0!\left(5-0\right)!}x^5y^0+\frac{5!}{1!\left(5-1\right)!}x^4y^1+\frac{5!}{2!\left(5-2\right)!}x^3y^2+\frac{5!}{3!\left(5-3\right)!}x^2y^3+\frac{5!}{4!\left(5-4\right)!}x^1y^4+\frac{5!}{5!\left(5-5\right)!}x^0y^5[/tex]

[tex]=x^5+5x^4y+10x^3y^2+10x^2y^3+5xy^4+y^5[/tex]

Therefore,

[tex]\left(x\:+y\right)^5=x^5+5x^4y+10x^3y^2+10x^2y^3+5xy^4+y^5[/tex]

You and your friend skate at the same rate. You complete 6 laps in 5 minutes. How long does your friend take to complete 18 laps?

Answers

Answer:

15 minutes

Step-by-step explanation:

Answer:

69

Step-by-step explanation:

haha 69= funny number

Which expression can be used to represent the phrase “Maren increases the number of servings by six”? A. n-6 B. 6-n C. n+6 D. 6n HURRY PLEASE

Answers

Answer: C) n+6

Step-by-step explanation:

You’re increasing so it means you want to add and you must have a serving 6+ and the only one that’s increasing is C

Answer: c is n+6

Step-by-step explanation:

At an amusement park, 25 riders ride the race cars every 30 minutes and 20 riders ride the spinning swings every 20 minutes. Which ride will have more riders each hour and how many more? Use the drop-down menus to answer the problem. The Choose... will have Choose... more riders each hour.

Answers

Answer:

The spinning swings will have 10 more riders each hour.

Step-by-step explanation:

1. If 25 riders ride the race car every 30 mins, that would mean each hour 50 riders ride the race car.

2. If 20 riders ride the spinning swings every 20 mins, that would mean each hour 60 riders ride the spinning swings.

Lets say 4 hours have passed. We could say 25 × 8. I don't know if this would make sense but there would be 8 30 mins in 4 hours. If you multiply 25 × 8 you would get 200 riders riding the race cars in 4 hours.

Lets do the same thing with the spinning swings. There are 12 20 mins in 4 hours. So we could do could do 20 × 12. That would equal 240 riders riding the spinning swings in 4 hours.

So if the race cars got 200 riders in 4 hours, each hours they will have 50 riders. And If the spinning swings got 240 riders in 4 hours, each hour they got 60 riders. So that would mean the spinning swings got more riders each hour. They also got 10 more riders each hour. Hopefully I didn't confused you.

(Ill give brainliest)


Solve 9,396 ÷ 18 = __________ Using partial quotients.
Draw it out

Answers

Answer:

522

Step-by-step explanation:

What is the slope and y-intercept of the equation: y = -2/3x + 5

Answers

Answer:

-2/3 is slope and y-intercept is 5

Write the slope intercept form of the equation of each line plz

Answers

the answer would be the first one :) y=-2x-4
The answer is y=-2x-4

The difference between two same side interior angles of two parallel lines is 35 degrees. Find the measures of these two angles.

Answers

Answer: 2x+43

Step-by-step explanation:

Answer:

107.5 degrees and 72.5 degrees (Don't forget the degrees symbol)

Please mark me Brainliest if I'm right :D

The incubation time for Rhode Island Red chicks is normally distributed with a mean of 21 days and a standard deviation of approximately 1 day. If 1000 eggs are being incubated, how many chicks do we expect will hatch?
a. In 19 to 23 days?
b. In 22 days or more?
c. In 21 days or fewer?
d. In 18 to 21 days?
e. In 19 days or fewer?
f. In 19 to 24 days?
g. In 18 to 24 days?
h. In 18 days or more?

Answers

Answer:

a - c

Step-by-step explanation:

if standard is 21 days then in incubator will hatch faster or at the same time but with high percentage of hatching a chick (btw hi from rhodes)

POINTS AND POINTS AND POINTS. ANSWER ONLY IF U TOOK THE TEST ON K12 AND POST PICTURE OF CORRECT ANSWERS.

The coordinates of the vertices of quadrilateral ABCD are A(−1, −1), B(−3, 3), C(1, 5), and D(5, 2). Drag and drop the choices into each box to correctly complete the sentences. The slope of AB⎯⎯⎯⎯⎯ is Response area, the slope of BC⎯⎯⎯⎯⎯ is Response area, the slope of CD⎯⎯⎯⎯⎯⎯ is Response area, and the slope of AD⎯⎯⎯⎯⎯ is Response area. Quadrilateral ABCD is Response area because Response area.

Answers

Answer:

AB=-2

BC=1\2

CD=-3\4

AD=1\2

Step-by-step explanation:

The slope of AB is - 2,

Slope of BC is

Slope of CD is

Slope of AD is ,

ABCD is trapezoid because one pair of opposite sides is parallel.

Answer:

slope of AB: -2

slope of BC: 1/2

slope of CD: -3/4

slope of AD: 1/2

Quadrilateral ABCD is a trapezoid because there is one pair of parallel sides.

Step-by-step explanation:

I solved for the slopes using slope formula. Also, I determined that the quadrilateral was a trapezoid since there was at least one pair of parallel sides. I'm sorry that I don't have a k12 account, but I hope this helps.

just a tad bit more points :)

Answers

Answer:

Thx have a great day :)

Step-by-step explanation:

yoink.

Thank you very much, kind sir/ma'am.

Have a nice day.

1 point
Find the slope of each line that passes through the points (4.0) and (7.9),

Answers

Answer:

[tex]m=3[/tex]

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Algebra I

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

Step-by-step explanation:

Step 1: Define

Point (4, 0)

Point (7, 9)

Step 2: Find slope m

Substitute:                    [tex]m=\frac{9-0}{7-4}[/tex]Subtract:                       [tex]m=\frac{9}{3}[/tex]Divide:                          [tex]m=3[/tex]

5
Select the correct answer.
Tom gets $12 off a box of chocolates that had an original price of $48. What percentage is the discount?
OA.
12%
OB.
25%
Ос.
50%
OD
60%
Reset
Next

Answers

Answer:

B

Step-by-step explanation:

12 is 1/4 of 48 so when you take $12 off $48 you take 1/4 of 25% away

Two system of equations 2y =14-2x and y=-x + 7 is graphed. What is the solution to the system of equations

Answers

Answer:

To solve this system, we will use the graphing method.

Based on the graph shown below, we can conclude that this system has infinite solutions, because they are the same line.

Answer:

Infinitely many solutions

Step-by-step explanation:

Given equations

2y =14-2x and y= -x + 7

Rewriting the first equation

2y = 14 - 2x2y = -2x + 14y = -x + 7

As we see it is same as the second equation. So same two lines, overlapping when graphed and the system has infinitely many solutions

HELP PLZ
i need help with this math side i just need b,c,d a =4x+2y=16

Answers

Answer:

Please check the explanatio.

Step-by-step explanation:

Solving Part b)

We know that the slope-intercept form of the equation line is

[tex]y=mx+b[/tex]

where m is the slope and b is the y-intercept

Given the equation

[tex]4x+2y=16[/tex]

Re-writing the equation in the slope-intercept form

[tex]4x+2y=16[/tex]

[tex]y=-2x+8[/tex]

Here, m=-2 and b=8

Thus, the equation in the slope-intercept form will be:

[tex]y=-2x+8[/tex]

Solving Part c)

As you sold two pounds of cheddar cheese.

i.e. y=2

substituting y=2 in the slope-intercept form of the line equation

[tex]y=-2x+8[/tex]

[tex]2=-2x+8[/tex]

Subtract 8 from both sides

[tex]-2x+8-8=2-8[/tex]

[tex]-2x=-6[/tex]

Divide both sides by -2

[tex]\frac{-2x}{-2}=\frac{-6}{-2}[/tex]

[tex]x=3[/tex]

You sold 3 pounds of swiss cheese.

Solving Part d)

[tex]y=-2x+8[/tex]

putting x=2.5 in the equation

[tex]y=-2x+8[/tex]

[tex]2=-2\left(2.5\right)+8[/tex]

[tex]2=3[/tex]

The sides are not equal

FALSE

Thus, x=2.5 does not make any sense in the context of the problem.

Jade practices tennis for 3.5 hours. Hayley only spends 0.75 hour practicing
tennis. How much more time does Jade spend practicing tennis than Hayley?

Answers

Answer:

2.75 hours

Step-by-step explanation:

3.5-0.75 which is 2.75.

So 2.75 hours.

Hope this helps :D

A basketball team played 15 games and won 80% of them. If the team expects to play 30 games in all, how many more games must it win to finish the season with a 90% winning percentage?
A. 12
B. 14
C. 15
D. 27​

Answers

Answer: C

Step-by-step explanation:

multiply 15 x 2

I NEEEDDDD HELP PLZZZZZZZZZZZZZZZZZZZZZZZZZ

The shorter diagonal of a rhombus measures 18cm. The side of the rhombus measures 41cm. Find the length of the longer diagonal.

Answers

Answer:

80 cm

Step-by-step explanation:

The diagonals divide the rhombus into four congruent triangles.  The height of each triangle is 18/2 = 9, and the hypotenuse is 41.  Using Pythagorean theorem, the width of each triangle is:

c² = a² + b²

41² = 9² + x²

x = 40

Therefore, the longer diagonal is 2×40 = 80.

The half-life of a radioactive substance is 200 years. There are 8000 grams of the substance initially. How many grams of the substance are left after 300 years?

Answers

Answer:

There are 2,000 grams left after 300 years.

Step-by-step explanation:

Giving the following information:

The half-life of a radioactive substance is 200 years. There are 8000 grams of the substance initially.

First, we need to calculate the reduction of the substance each year:

Yearly reduction= 8,000/400= 20 grams per year

Now, for 300 years:

300 year reduction= 20*300= 6,000

There are 2,000 grams left after 300 years.

Carter's trampoline has a diameter of 10 ft. Its circumference is twice as great as the circumference of Reed's trampoline. What is the circumference of Reed's trampoline.​

Answers

Answer:

no

Step-by-step explanation:

nsjdjfhfjskskdknxiwiwfbrbbewiisaksndbbfeueiaooand

Let be a continuous random variable that follows a normal distribution with a mean of and a standard deviation of . Find the value of so that the area under the normal curve to the right of is . Round your answer to two decimal places.

Answers

Complete Question

Let x be a continuous random variable that follows a normal distribution with a mean of 550 and a standard deviation of 75.

a

Find the value of x so that the area under the normal curve to the left of x is .0250.

b

Find the value of x so that the area under the normal curve to the right ot x is .9345.

Answer:

a

  [tex]x = 403[/tex]

b

 [tex]x = 436.75[/tex]

Step-by-step explanation:

From the question we are told that

   The  mean is  [tex]\mu = 550[/tex]

   The standard deviation is  [tex]\sigma = 75[/tex]

Generally the value of x so that the area under the normal curve to the left of x is 0.0250 is mathematically represented as

     [tex]P( X < x) = P( \frac{x - \mu }{ \sigma} < \frac{x - 550 }{75 } ) = 0.0250[/tex]

[tex]\frac{X -\mu}{\sigma }  =  Z (The  \ standardized \  value\  of  \ X )[/tex]

     [tex]P( X < x) = P( Z < z ) = 0.0250[/tex]

Generally the critical value of  0.0250 to the left  is  

       [tex]z = -1.96[/tex]

=>    [tex]\frac{x- 550 }{75} = -1.96[/tex]

=>    [tex]x = [-1.96 * 75 ]+ 550[/tex]      

=>    [tex]x = 403[/tex]

Generally  the value of x so that the area under the normal curve to the right of x is 0.9345 is mathematically represented as

        [tex]P( X < x) = P( \frac{x - \mu }{ \sigma} < \frac{x - 550 }{75 } ) = 0.9345[/tex]

[tex]\frac{X -\mu}{\sigma }  =  Z (The  \ standardized \  value\  of  \ X )[/tex]

     [tex]P( X < x) = P( Z < z ) = 0.9345[/tex]

Generally the critical value of  0.9345 to the right  is  

       [tex]z = -1.51[/tex]

=>    [tex]\frac{x- 550 }{75} = -1.51[/tex]

=>    [tex]x = [-1.51 * 75 ]+ 550[/tex]      

=>    [tex]x = 436.75[/tex]

   

     

Ricky walked a total of 4 3/4

miles on the school track. He stopped every 1/4

mile to rest.

Rick stopped ​
times to rest. Round your answer to the nearest whole number, if necessary.

Answers

Answer:

19

Step-by-step explanation:

Is he stop every 1/4 mile you get 19

There are 4 1/4 miles in every mile. 4x4(Equation of total 1/4th's in 4 miles) is 16. Add 3 more 1/4th's to get 19

Hope this helps!

Total number of rest is 19 times

Fraction based problem:

Given that;

Distance walked by Ricky = 4³/₄ miles = 19 / 4 miles

rest on every mile = 1/4 miles

Find:

Total number of rest

Computation:

Total number of rest = Distance walked by Ricky ÷ Rest on every mile

Total number of rest = [19 / 4] ÷ [1 / 4]

Total number of rest = 19 times

Find out more information about 'Distance'.

https://brainly.com/question/26711747?referrer=searchResults

Which equation represents a line that passes through the two points in the
table?

Answers

Answer:

C

Step-by-step explanation:

use the points to find the slope (y-y1/x-x1) 3-5/3-6 = 2/3

the answers are all in point slope form so the slope is 2/3 and the point represented is 3,3

Answer: It’s A. Just did it

Step-by-step explanation:

(03.01) Match the two numbers with their least common multiple (LCM). Match Term Definition 8 and 4 A) 24 8 and 6 B) 8 8 and 10 c) 40 Previous Question Question 1 (Not Answered)​

Answers

Answer:

LCM of 8 and 4 = [tex]8[/tex]

LCM of 8 and 6  [tex]=24[/tex]

LCM of 8 and 10 = [tex]40[/tex]

Step-by-step explanation:

Least common multiple (LCM) of numbers is their smallest common multiple.

First find prime factorization of [tex]4,6,8,10[/tex]

[tex]4=2^2\\6=2(3)\\8=2^3\\10=2(5)[/tex]

LCM of 8 and 4 = [tex]2^3=8[/tex]

LCM of 8 and 6  [tex]=2^3(3)=8(3)=24[/tex]

LCM of 8 and 10 = [tex]2^3(5)=8(5)=40[/tex]

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