Answer:
<em>M(13)=14.3 gram</em>
Step-by-step explanation:
<u>Exponential Decay Function</u>
The exponential function is used to model natural decaying processes, where the change is proportional to the actual quantity.
An exponential decaying function is expressed as:

Where:
C(t) is the actual value of the function at time t
Co is the initial value of C at t=0
r is the decaying rate, expressed in decimal
The element has an initial mass of Mo=970 grams, the decaying rate is r=27.7% = 0.277 per minute.
The equation of the model is:


Operating:

After t=13 minutes the remaining mass is:

Calculating:
M(13)=14.3 gram
15x+40=115
15x means 15 per week solve for x if you want to know how many weeks 40 is what he has only once
Answer:
18
Step-by-step explanation:
Honestly you can just use a calculator for this.
But if you want to know how to actually do it, multiplying something by a fraction is just dividing it by its reciprocal (just flipping the numerator and the denominator).
Therefore...
72/4 is 18, 72 x 1/4 = 18
You can solve this by finding all of the factors of 28 and seeing which ones add up to 22 when doubled.
The factors of 28 are as follows:
28 x 1 28(2) + 1(2) = 56 + 2 = 58 ≠ 22
14 x 2 14(2) + 2(2) = 28 + 4 = 32 ≠ 22
7 x 4 7(2) + 4(2) = 14 + 8 = 22
The dimensions of the rectangle are 4 x 7.
The time taken for the element X to decay from 560 grams to 150 grams is 24.7 mins
<h3>How to determine the number of half-lives </h3>
- Original amount (N₀) = 560 g
- Amount remaining (N) = 150 g
- Number of half-lives (n) =?
2ⁿ = N₀ / N
2ⁿ = 560 / 150
2ⁿ = 3.73
Take the log of both side
Log 2ⁿ = Log 3.73
nLog 2 = Log 3.73
Divide both side by Log 2
n = Log 3.73 / Log 2
n = 1.9
<h3>How to determine the time </h3>
- Number of half-lives (n) = 1.9
- Half-life (t½) = 13 mins
t = n × t½
t = 1.9 × 13
t = 24.7 mins
Learn more about half life:
brainly.com/question/26374513