Answer: t-half = ln(2) / λ ≈ 0.693 / λExplanation:The question is incomplete, so I did some research and found the complete question in internet.
The complete question is:
Suppose a radioactive sample initially contains
N0unstable nuclei. These nuclei will decay into stable
nuclei, and as they do, the number of unstable nuclei that remain,
N(t), will decrease with time. Although there is
no way for us to predict exactly when any one nucleus will decay,
we can write down an expression for the total number of unstable
nuclei that remain after a time t:
N(t)=No e−λt,
where λ is known as the decay constant. Note
that at t=0, N(t)=No, the
original number of unstable nuclei. N(t)
decreases exponentially with time, and as t approaches
infinity, the number of unstable nuclei that remain approaches
zero.
Part (A) Since at t=0,
N(t)=No, and at t=∞,
N(t)=0, there must be some time between zero and
infinity at which exactly half of the original number of nuclei
remain. Find an expression for this time, t half.
Express your answer in terms of N0 and/or
λ.
Answer:
1) Equation given:
← I used α instead of λ just for editing facility..
Where No is the initial number of nuclei.
2) Half of the initial number of nuclei:
N (t-half) = No / 2So, replace in the given equation:
3) Solving for α (remember α is λ)
αt ≈ 0.693
⇒ t = ln (2) / α ≈ 0.693 / α ← final answer when you change α for λ
#1 is 2 #2 is 6 i dont know 3
Answer:
131.6 Newtons
Step-by-step explanation:
30 ÷ 0.228 =131.6 Newtons
8x + 16 = 14x
To solve this equation, move everything containing the variable you want to solve for on one side of the equation and everything else to the other side of the equation.
Let's start by subtracting 8x from both sides to have the variable x all on the right side of the equation. Once you subtract 8x from both sides, your equation will now look like this:
16 = 6x
To solve for the variable x, you want to divide both sides of the equation by 6 to isolate x and therefore find your answer. Divide both sides by 6 and your equation should look like this:
16/6 = x
Simplifying 16/6 into a mixed number ⇒ 2 2/3
Your answer is x = 16/6 or 2 2/3.
Answer:
A sample size of 554 is needed.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.96.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
Standard deviation is known to be $12,000
This means that 
What sample size do you need to have a margin of error equal to $1000, with 95% confidence?
This is n for which M = 1000. So



Dividing both sides by 1000:



Rounding up:
A sample size of 554 is needed.