The sum of two numbers is 72 and their difference is 26. find two numbers?
1 answer:
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Answer: t-half = ln(2) / λ ≈ 0.693 / λ
Explanation:
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:
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 / 2
So, 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
Explanation:
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:
Where No is the initial number of nuclei.
2) Half of the initial number of nuclei: N (t-half) = No / 2
So, 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:
x=6, AB=61, BC=61, AC=122
Step-by-step explanation:
Answer:
The quadratic equation form is x² - 9 x + 14 = 0
Step-by-step explanation:
Given in the question as ,
The solution of quadratic equation are x = 2 and x = 7
The constant K is a non-zero number
Now , let the quadratic equation be , ax² + bx + c = 0
And sum of roots =
product of roots =
So, 2 + 7 =
Or, 2 × 7 =
I.e = 9 ,
= 14
Or, b = - 9 a And c = 14 a
Put this value of b and c in standard form of quadratic equation
I.e ax² + bx + c = 0
Or, ax² - 9 ax + 14 a = 0
Or , a ( x² - 9 x + 14 ) = 0
∴ a = 0 And x² - 9 x + 14 = 0
Hence , The quadratic equation form is x² - 9 x + 14 = 0 Answer