Answer:
Rock D.
Step-by-step explanation:
We can assume that the force that the catapult does is always the same.
So, here we need to remember Newton's second law:
F = m*a
force equals mass times acceleration.
Where acceleration is the rate of change of the velocity.
So, if we want the rock to hit closer to the catapult, the rock must be less accelerated than rock B.
So, we can rewrite:
a = F/m
So, as larger is the mass of the rock, smaller will be the acceleration of the rock after it leaves the catapult (because the mass is in the denominator). So if we want to have a smaller acceleration, we need to choose a rock with a larger mass than rock B.
Assuming that the mass depends on the size, the only one that has a mass larger than rock B is rock D.
So we can assume that rock D is the correct option.
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:6.6 y
Step-by-step explanation:
Answer:
The statement is false
Step-by-step explanation:
Given
See comment for complete statement
Required
Is the statement true or false
From central limit theorem, we understand that a distribution is approximately normal if the distribution takes a sample considered to be large enough from the population.
Also, the mean and the standard deviation are known.
However, the given statement implies that the distribution will be normal depending on an underlying distribution; this is false.