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
wel
3 years ago
15

PLEASE HELP!!!

Mathematics
2 answers:
ludmilkaskok [199]3 years ago
4 0

Answer:

The half life of the substance is 6.0 days.

Step-by-step explanation:

The initial equation for the initial mass and mass at time t is;

                                N = N_{0} e^{-kt}

Where N is the mass at time t, N_{0} is the initial mass, k is the constant and t is the half life. After the half life i.e t,

So that at a given time t, N_{0} = 33 grams and N = 16.5 grams

        ⇒       16.5 = 33 e^{-kt}

                  16.5 = \frac{33}{e^{kt} }

cross multiply, we have;

                e^{kt} = \frac{33}{16.5}

                  e^{kt} = 2

Find the natural logarithm of both sides,

          ln e^{kt}  = ln2

          kt = ln2

 ⇒     t = \frac{ln2}{k}

         t = \frac{0.6932}{0.1142}

         t = 6.07

The half life of the substance is 6.0 days.

 

Aneli [31]3 years ago
3 0
From the attached graphic, Half-life = ln (.5) / k

Half-life =.693147 / <span>0.1142
= </span><span><span><span>6.0695884413 </span> days

The value of "k" should be negative and should have units associated with it.
</span> </span>

You might be interested in
If g(x) is an odd function, which function must be an even function?
babunello [35]

Answer:

<em>f(x)=(g(x))^2 is an even function.</em>

Step-by-step explanation:

We are given that g(x) is an odd function.

we have to determine that among the four options which are an even function.

(a)  f(x)=g(x)+2

let g(x)=x ; is an odd function.

Then f(x)=x+2

on computing f(-x)= -x+2

We see that f(-x)≠f(x).

Hence f(x) is not an even function.

Hence, option (a) is incorrect.

(b) f(x)=g(x)+g(x)=2g(x)

as g(x) is an odd function.

so let g(x)=x

f(x)=2x

f(-x)= -2x.

here also we get f(-x)≠f(x).

Hence f(x) is not an even function.

(d) f(x)= -g(x)

Let g(x)=x which is an odd function.

Then f(x)= -x

also f(-x)=x

Here also f(-x)≠f(x)

Hence f(x) is not an even function.

Hence (a),(b) and (d) are incorrect. We are left with option (c).

Also let us consider :

(c) f(x)= (g(x))^2

as square of an odd function is an even function.

Hence f(x) is an even function.




8 0
3 years ago
Read 2 more answers
You calculated the standard deviation of the sample mean differences to be .69. You also calculated the sample mean difference t
solong [7]

Answer:

Since |Z| = 2.52 > 2, the difference is significant.

Step-by-step explanation:

Z-score:

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

If |Z| > 2, the measure X is significent.

In this question:

|X - \mu = 1.74|, \sigma = 0.69

So

Z = \frac{1.74}{0.69} = 2.52

Since |Z| = 2.52 > 2, the difference is significant.

4 0
4 years ago
Activity
mina [271]

Answer:

Factor, in mathematics, a number or algebraic expression that divides another number or expression evenly—i.e., with no remainder. For example, 3 and 6 are factors of 12 because 12 ÷ 3 = 4 exactly and 12 ÷ 6 = 2 exactly. The other factors of 12 are 1, 2, 4, and 12. A positive integer greater than 1, or an algebraic expression, that has only two factors (i.e., itself and 1) is termed prime; a positive integer or an algebraic expression that has more than two factors is termed composite. The prime factors of a number or an algebraic expression are those factors which are prime. By the fundamental theorem of arithmetic, except for the order in which the prime factors are written, every whole number larger than 1 can be uniquely expressed as the product of its prime factors; for example, 60 can be written as the product 2·2·3·5.

3 0
3 years ago
A six-sided die with sides labeled 1 through 6 will be rolled once. Each number is equally likely to be rolled. What is the prob
Trava [24]

Answer:

4/6 or 2/3. Depends if your teacher wants it reduced.

Step-by-step explanation:

Each number has a 1 out of 6 chance to be rolled. so it's 1/6 for rolling a 3, 1/6 for rolling a 4, 1/6 for rolling a 5, and 1/6 for rolling a 6. 4 x 1/6 = 4/6

5 0
3 years ago
What percent is equivalent to 1/25?​
oksano4ka [1.4K]

Answer:

4%

25 x FOUR is 100 so 4 is the answer

5 0
3 years ago
Read 2 more answers
Other questions:
  • If an account is increasing at a rate of 3.3% compounded semiannually, what is the exact value of in the following present value
    6·1 answer
  • I need help with this problem?
    11·1 answer
  • Two addends which make a sum of 12
    14·1 answer
  • Can you give me an equation that has the answer 26 ?
    8·1 answer
  • A circle has a diameter of 4 meters.<br> What is its perimeter (to the nearest hundredth)?
    10·2 answers
  • I need help! I don't understand!
    13·1 answer
  • In ΔDEF, the measure of ∠F=90°, the measure of ∠D=70°, and EF = 4.4 feet. Find the length of FD to the nearest tenth of a foot.
    13·1 answer
  • PRACTICE
    8·1 answer
  • Someone please help! im kinda in a rush
    8·1 answer
  • Tell me the Characteristics of a Reflection
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!