one isotope of chromium has a half life of 18 hours. How long does it take 100 grams to decay to 20 grams?

Answers

Answer 1

Answer:

41.79 hours

Step-by-step explanation:

The Half-time Decay Formula: [tex]N=N_0(\frac{1}{2})^\frac{t}{d}[/tex]

Where [tex]N_0[/tex] is the original number, and t = time, and d = time it takes to half

18 would be d

100 would be [tex]N_0[/tex]

and 20 would be N

[tex]20=100(\frac{1}{2})^\frac{t}{18}[/tex]

[tex]0.2=(\frac{1}{2})^\frac{t}{18}[/tex]

[tex]log_\frac{1}{2}0.2=\frac{t}{18}[/tex]

[tex]18* log_\frac{1}{2}0.2=t[/tex]

[tex]18* \frac{log_{10}0.2}{log_{10}\frac{1}{2}}=t[/tex]

= 41.79470571


Related Questions

i need help with geometry!!

Answers

Answer:

1 - 178cm

2 - 1,039.2 m

Step-by-step explanation:

Find the mean, median, and mode. Plz help me it’s a test

Answers

Answer:

Mean- 70.8

Median- 70

Mode- 60

Step-by-step explanation:

Mean: 20+20+50+50+50+60+60+60+60+60+60+70+70+70+80+80+80+80+90+90+90+90+100+100+130= 1770

1770/ 25= 70.8

Median: cross off on each sides till you get to the middle number

Mode: 60 occurs the most frequent

hello pls help me. khan academy sucks

Answers

Answer:

straight angle

i think straight angle is right answer

Please explain how - calc ab - see attached photo

Answers

Answer:

D

Step-by-step explanation:

Set up to different integrals that match the endpoints

so in our case it would look like

[tex]\int\limits^0_{-2} {x} \, dx +\int\limits^1_0 {x+1} \, dx[/tex]

now it's just a matter of computing it

[tex]\int\limits^0_{-2} {x} \, dx =x^2\\0^2-(-2)^2=4\\\int\limits^1_0 {x+1} \, dx =\frac{x^2}{2}+x\\\frac{1}{2}+1-0=\frac{3}{2}\\\frac{3}{2}+4=\frac{11}{2}[/tex]

Rectangle has a vertices at (-1,4), (-1,-1) and (4, -1) where is the fourth vertex located

Answers

Answer:

(4,4)

Step-by-step explanation:

1. I drew a grid and plotted the 3 points I already knew

2. I found the spot that had the same x coordinate that the point to the bottom left of the shape, and the same y coordinate of the top right of the shape which was the point (4,4)

I hope this helps!!


Last year, a population of rabbits had 20 births, 10 deaths, 15 individuals immigrate, and 15 individuals emmigrate.
What is the change in population size for the rabbits that year?

Answers

Answer:

+10

Step-by-step explanation:

35 - 25 = 10. I got 35 because 20 + 15 from the bunnies immigrating and 25 from the deaths and bunnies emmigrating out of the population.

NEED HELP ASAP PLEASE PRETTY SIMPLE TYSM

Answers

Answer:

[tex]2x + 3y = 6 ---(1)\\y = \frac{x}{6} - 3 ----(2)\\\\substitute \ y \ in \ (1)\\2x + 3(\frac{x}{6} - 3) = 6\\\\2x + \frac{x}{2} - 9 = 6\\\\\frac{5x}{2} = 6+9\\\\\frac{5x}{2} = 15\\5x = 30 \\x = 6\\substitute \ x \ in \ (2)\\\\y = \frac{6}{6} -3 = 1 - 3= -2[/tex]

x = 6, y = -2

A wheel with a 1 foot radius spins in place in a counterclockwise direction. Explain why the distance point P travels is the same as the angle of revolution (measured in radians) of this wheel?

Answers

Answer:

See below.

Step-by-step explanation:

The definition of radian is:

A radian is a unit of angle measurement such that a central angle of a circle measuring 1 radian subtends and arc of the circle whose length equals the radius if the circle.

In this case, the radius is 1 foot. Point P travels along the arc formed by an angle. When the angle is 1 radian, the arc length equals the radius of the circle, 1 foot. It is simply following the definition of radian.

Point P will travel a distance in a complete revolution i.e. the distance point P travels is the same as the angle of revolution.

What is 1 radian?

One radian is defined as the angle subtended from the centre of a circle which intercepts an arc equal in length to the radius of the circle.

Circumference of the circle = 2π(1) =2π feet.

This means point P will travel a distance in a complete revolution.

A complete revolution = 360° or 2π

Hence, point P will travel a distance in a complete revolution i.e. the distance point P travels is the same as the angle of revolution.

To get more about circles visit:

https://brainly.com/question/24375372


Select all the right triangles, given the lengths of the sides.

Answers

Answer:

A and E are right triangles

Triangles A and triangle E are the right-angle triangle, but triangles B, C, and D are not right-angle triangles.

What is the right triangle?

A right-angle triangle is a triangle that has a side opposite to the right angle the largest side and is referred to as the hypotenuse. The angle of a right angle is always 90 degrees.

The slanted side of that triangle is called Hypotenuse and it is the longest side in that triangle.

Applying in Pythagoras theorem in the triangle A:

(√5)² = (√2)²+ (√3)²

5 = 5

Triangle A is the right-angle triangle.

For triangle B:

(√5)² = (√4)²+ (√3)²

5 ≠ 7

Triangle B is not the right-angle triangle

For triangle C:

16 + 25 ≠ 36

triangle C is not a right-angle triangle

For  triangle D:

25 + 25 ≠ 49

triangle D is not a right-angle triangle

For triangle E:

100 = 36 + 64

It is a right-angle triangle.

Thus, triangles A and triangle E is the right angle triangle.

Learn more about a right angle;

https://brainly.com/question/7116550

#SPJ2

Here!! no links please

Answers

Answer:

area = 66.28 km²

Step-by-step explanation:

area = (8 x 2) + (11 x 4) + (3.14)(2²)(0.5) = 16 + 44 + 6.28 = 66.28 km²

Answer:

Solution given:

area of semi circle=½×π×r²=½π×2²=6.28km²

area of rectangle ABCD=L×b=3×4=12km²

area of rectangle EFGC=L×b=8×6=48km²

total area =6.28+12+48=66.28 square kilometers.

Can someone help me plzz!! no links tho​

Answers

Answer:

A

Step-by-step explanation:

The quadrilateral shown is a rectangle. What is measure zvw

Answers

Answer:

measure of zvm is 119°

Step-by-step explanation:

xvw+zvw=180°{straight angle}zvm=180-61=119°

stay safe healthy and happy.

This is easy I just need the answer thanks!!! :)

Answers

Answer:

225 inches

Step-by-step explanation:

15 x 15 = 225

Examine the expression. 17x - 34 Which is an equivalent expression? O 17*(1 + ) O 17x (1-2) O 17+(1-1) O 17*(1 + 2)​

Answers

Answer:

17(x-2)

Step-by-step explanation:

Given the expression

17x - 34

We are to factorize it

Get their factors

17x = 17 * x

34 = 17 * 2

Since 17 is common to both factors, hence 17 is the GCF

17x - 34 = 17(x - 2)

Hence the equivalent expression is 17(x-2)

Can somebody help me out my grade are bad

Answers

Answer:

I would make a triangle

Step-by-step explanation:

Answer:

Step-by-step explanation:

Samuel wants to buy cookies for his friend. The diameter of a cookie is 20 inches. What is the cookies area? Round to the nearest hundredth

Answers

Answer:

314.16

Step-by-step explanation:

Area=πr2

d=2r

Solving for Area

A=1

4πd2=1

4·π·202≈314.15927

Please help me find the range!

Answers

The range would be 0

if 2/3x - 1 = 4 then x = ?

Answers

Answer: 2/15

Step-by-step explanation:

2/3x-1(3x/3x)=4

2/3x-3x/3x=4

2-3x=12x

2=15x

x=2/15

Fabric is on sale for these prices: orange, $3 per yard; blue, $4 per yard; yellow, $2.50 per yard; and white $1.50 per yard. Irma needs to buy 3 different colors of fabric with a total length of 2 yards. She has a budget of $6. What fabrics could she buy?

Answers

Answer:

Yellow White And Orange I pretty Sure!! Im sorry if this is not what you want! I can change it if so.

Step-by-step explanation:

A rectangular swimming pool has a base with measurements of 25 meters and 17 meters. The height of the pool is 2 meters, what is the volume of the pool

Answers

Answer:

850m³

Step-by-step explanation:

Volume is length X width X height.

So, 25 x 17 x 2 = 850 meters cubed

I need help with this question. check your solution please show WORK please. 5 = x + 8

Answers

Answer:

x = -3

Step-by-step explanation:

5 = x + 8

You need to get x by Itself so subtract 8 to both sides.

5 - 8 = -3

so therefore x = - 3

The Old-Fashioned but Newfangled Candy Company wants to mix some of its $5.50 per pound Tropical Taffy, with 100 pounds of its $6.25 per pound Passion Fruit Taffy to create a $6 per pound taffy called Tropical Passion. How many pounds of the $5.50 per pound Tropical Taffy should the company use?​

Answers

Answer:

50

Step-by-step explanation:

x= the number of pounds of the tropical taffy that should be used

You need to take the value of the Tropical Taffy + the value of the Passion Fruit taffy to = the value of Tropical Passion

value- price per pound times the number of pounds

Your equation is going to look like this-->

5.50x+6.25(100)=6(x+100)

5.50x+625=6x+600

-5.50x        -5.50x

625=0.5x+600

-600         -600

25=0.5x

50=x

Hope this helps!

What is the area of this square?​

Answers

Answer:

100

Step-by-step explanation:

Formula is bh (Base times Height)

so 10 * 10

Hope this helped :]

Answer:

100 m

Step-by-step explanation:

Area is found by multiplying the length and height of a shape. The length and height of the square are both 10 m.

10 ⋅ 10 = 100

4) Write the equation for the line of best fit shown in the graph below. Show all your work.
(3 points)

Answers

Answer:

3y = 2x+6

Drawing:

THIS IS URGENT PLZ HELP!!!

Find three consecutive EVEN numbers such that: The sum of one sixth of the first number, two sevenths of the second number and one half of the third number equals 54

Answers

Answer:

12

Step-by-step explanation:

2

4

6

8

10

12

14

16

18

20

22

24

26

Help please!! ASAP!!

Thanks!!

Answers

Answer:

402

Step-by-step explanation:

The standard formula for the nth term of an arithmetic sequence is:

t + (n - 1)d

where t is the first term and d is the common difference. We can substitute to create a system of equations to solve for the first term and common difference:

22 = t + (5 - 1)d

62 = t + (15 - 1)d

22 = t + 4d

62 = t + 14d

We can use elimination to cancel out t:

62 = t + 14d

-( 22 = t + 4d )

40 = 10d

d = 4

Now, we can substitute the common difference to find the first term:

22 = t + 4*4

22 = t + 16

t = 6

Lastly, we can substitute values in the first equation to find the 100th term:

a100 = t + (n - 1)d

a100 = 6 + (100 - 1)(4)

a100 = 6 + (99)(4)

a100 = 6 + 396

a100 = 402

the answer is 402 since the equation is a5

In a right triangle, angle φ has a tangent value of 1.40. The side adjacent to angle φ has a length of 9.0 inches. What is the length of the side opposite angle φ?
a. 6.4 inches
b. 12.6 inches
c. 9.1 inches
d. 54.4 inches

Answers

Answer:

b) 12.6 inches

Step-by-step explanation:

tangent is the ratio of the side opposite over adjacent, so if we let x= length of the opposite side, 1.40=x/9, x=12.6 inches

b) 12.6 inches

Hope it helps!!

I will give brain list

Answers

Answer:

Step-by-step explanation:

20/100 + 4/10 =20/100 + x = x move a fraction to make the equation true

Answers

Answer:

remove 4/10

20/100=20/100= 1 which is x

Step-by-step explanation:

Mrk ME BRAINLIEST PLZZZZZZZZZZ

Can you help me please

Answers

Answer:

∠1 = 48

∠2 = 132

∠4 - 132

Step-by-step explanation:

∠3 and ∠1 are vertical angles

vertical angles are congruent ( equal to each other )

So if ∠3 = 48° then ∠1 also = 48°

∠3 and ∠4 are supplementary angles

supplementary angles add up to equal 180°

Hence, ∠3 + ∠4 = 180

48 + ∠4 = 180

180 - 48 = 132

Hence, ∠4 = 132

∠4 and ∠2 are vertical angles

Like stated previously vertical angles are congruent

Hence, ∠2 = 132

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