1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
shepuryov [24]
3 years ago
9

I know you have to use the half life formula but I don’t know how to use it could someone show how to find the solution step by

step? Thank you

Mathematics
1 answer:
n200080 [17]3 years ago
7 0

Answer:

A = Pe ^{-0.03108 * t}

Step-by-step explanation:

Note: these are typically two part questions...

you have the model and have to FIRST find a constant value "k"

once you have the "k" value you plug that into the model to finish the problem

A = Pe ^{-kt} is a typical version of the continuous decay...

e is "e 2.717" not a variable "e"

so... step 1.. fink k

you are told that the 1/2 life is 22.3 years...

so lets assume that we started with 2 units of lead, and waited for it to decrease to 1 (1 is 1/2 of 2)

you would have

1 = 2e^{k * 22.3}

.5 = e^{k * 22.3}

ln(.5) = 22.3k ln(e)

ln(e) = 1

ln(.5) = 22.3k

ln(.5) = 22.3k ln(e)

\frac{ln(.5) }{22.3} = k

\frac{\ln \left(0.5\right)}{22.3}=-0.03108 = k

You might be interested in
Plzz im dumb i need your help
likoan [24]

Answer:

a

Step-by-step explanation:

3 0
3 years ago
Of all of the individuals who develop a certain rash, suppose the mean recovery time for individuals who do not use any form of
VashaNatasha [74]

Answer:

z(s) is in the rejection  region. We reject  H₀. We dont have enought evidence to support that the cream has effect over the recovery time

Step-by-step explanation:

Sample information:

Size     n = 100

mean   x = 28,5

Population information

μ₀  =  30

Standard deviation  σ   = 8

Test Hypothesis

Null Hypothesis          H₀                x =  μ₀

Alternative Hypothesis   Hₐ           x <  μ₀

We assume CI = 95 %   then α = 5 %    α = 0,05

As the alternative hypothesis suggest we should develop a one tail-test on the left ( we need to find out if the cream have any effect on the rash), effects on the rash could be measured as days of recovery

A z(c) for 0,05 from z-table is:  z(c) = - 1,64

z(s) = ( x - μ₀ ) / σ/√n

z(s) = ( 28,5 - 30 ) / 8/√100

z(s) = - 1,5 * 10 / 8

z(s) =  - 1,875

Comparing z(s)  and z(c)

|z(s)| < |z(c)|        1,875  > 1,64

z(s) is in the rejection  region. We reject  H₀. We dont have enought evidence to support that the cream has effect over the recovery time

3 0
3 years ago
Danielle put 4.902 gallons of gasoline in a gas tank. What is 4.902 written in expanded form?
QveST [7]

Answer:

a

Step-by-step explanation:

6 0
3 years ago
PLEASE HELP FIRST GETS BRAINLIEST!!!!!!!!!!!
Shalnov [3]
Four people read 6to 8 books.
7 0
4 years ago
Read 2 more answers
Help please<br> ......................
seropon [69]
1. 35x + 0.15y
=3500x + 15y [multiplying the equation by 100]
= 700x + 3y [dividing the equation by 5]

2. Let x be an even integer
x + (x+2) + (x+2+2)
x+x+2+x+4
3x+6

3. 1/5*(r+7) - 9s
(r+7)/5 - 9s

4. x=cows
y= goats + sheep

x= (y+140)/2
7 0
3 years ago
Read 2 more answers
Other questions:
  • HELP PLEASE. Find x &amp; y round answer to the nearest tenth!
    8·1 answer
  • When do you can ride her bike .8 miles in six minutes how many miles can she ride her bike and 1.5 hours
    5·1 answer
  • Find the 61st term of the arithmetic sequence -12,-28,-44...
    5·1 answer
  • Which of the following can be used to prove that triangle EFG is also a right triangle?
    6·1 answer
  • 3(x−2)=9 :solve for x?
    6·2 answers
  • 99. For an outdoor event, Nathan will wear a
    7·1 answer
  • Who here knows how to construct a hexagon using a compass,straight-edge, and circle.
    6·1 answer
  • Suppose that you deposit $1. 200 at the end of each year for 40 years, Subject to annual compounding at a constant rate of 5%. F
    15·1 answer
  • Find the perimeter of the triangle.
    5·1 answer
  • I need some help with this two.
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!