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
Answer:
The answer to your question is speed = 81.5 mi/h
Step-by-step explanation:
Data
distance = 230 ft
time = 1.932 s
speed = ? mi/h
Process
1.- Convert the distance to mi
1 mile ----------------- 5280 ft
x ----------------- 230 ft
x = (230 x 1) / 5280
x = 0.044 mi
2.- Convert time to hours
1 h ------------------ 3600 s
x ------------------ 1.932 s
x = (1.932 x 1) / 3600
x = 0.00054 h
3.- Calculate the speed
speed = distance / time
-Substitution
speed = 0.044/ 0.00054
-Result
speed = 81.5 mi/h
Since z is the midpoint, rz and zt must be equal
4x - 15 = 25
4x = 40
X = 10
Plug the answer in and rz equals 40-15 which is 25.
25 + 25 = 50
Or if you really wanted, since you know 25 is half, just add them together right off the bat. (25 and 25, I mean)
Answer:
(-1,3)
Step-by-step explanation:
The slope is given by
m = (y2-y1)/(x2-x1)
1 = (2-3)/(-2-x)
Multiply each side by (-2-x)
(-2-x) = -1
Multiply by -1
2+x = 1
Subtract 2 from each side
2+x-2 = 1-2
x = -1