Answer:
Is this in Deltamath?
Step-by-step explanation:
Answer:
see below
Step-by-step explanation:
The equation for half life is
n = no e ^ (-kt)
Where no is the initial amount of a substance , k is the constant of decay and t is the time
no = 9.8
1/2 of that amount is 4.9 so n = 4.9 and t = 100 years
4.9 = 9.8 e^ (-k 100)
Divide each side by 9.8
1/2 = e ^ -100k
Take the natural log of each side
ln(1/2) = ln(e^(-100k))
ln(1/2) = -100k
Divide each side by -100
-ln(.5)/100 = k
Our equation in years is
n = 9.8 e ^ (ln.5)/100 t)
Approximating ln(.5)/100 =-.006931472
n = 9.8 e^(-.006931472 t) when t is in years
Now changing to days
100 years = 100*365 days/year
36500 days
Substituting this in for t
4.9 = 9.8 e^ (-k 36500)
Take the natural log of each side
ln(1/2) = ln(e^(-36500k))
ln(1/2) = -36500k
Divide each side by -100
-ln(.5)/36500 = k
Our equation in years is
n = 9.8 e ^ (ln.5)/36500 d)
Approximating ln(.5)/365=-.00001899
n = 9.8 e^(-.00001899 d) when d is in days
We have been given that you invest $100,000 in an account earning 8% interest compounded annually. We are asked to find the time it will take the amount to reach $300,000.
We will use compound interest formula to solve our given problem.
, where,
A = Final amount after t years,
P = Principal amount,
r = Annual interest rate in decimal form,
n = Number of times interest is compounded per year,
t = Time in years.
Let us take natural log on both sides of equation.
Using natural log property 
, we will get:
Upon rounding to nearest tenth of year, we will get:
Therefore, it will take approximately 14.3 years until the account holds $300,000.
Answer:1800 words
Step-by-step explanation:
Multiply how many words per minute she types by how many minutes she types. In this case 60x30=?. The easy way to do this is drop the 2 zeros and do 6x3=18. In the original equation we dropped the 2 zeros. Now we add them back on the back of the 18 and get 1800.
