Half life formula
The number of unstable nuclei remaining after time t can be determined according to this equation:
N(t) = N(0) * 0.5^(t/T)
where:
N(t) is the remaining quantity of a substance after time t has elapsed.
N(0) is the initial quantity of this substance.
T is the half-life.
It is also possible to determine the remaining quantity of a substance using a few other parameters:
N(t) = N(0) * e^(-t/τ)
N(t) = N(0) * e^(-λt)
τ is the mean lifetime - the average amount of time a nucleus remains intact.
λ is the decay constant (rate of decay).
All three of the parameters characterizing a substance's radioactivity are related in the following way:
T = ln(2)/λ = ln(2)*τ
How to calculate the half life
Determine the initial amount of a substance. For example, N(0) = 2.5 kg.
Determine the final amount of a substance - for instance, N(t) = 2.1 kg.
Measure how long it took for that amount of material to decay. In our experiment, we observed that it took 5 minutes.
Input these values into our half life calculator. It will compute a result for you instantaneously - in this case, the half life is equal to 19.88 minutes.
If you are not certain that our calculator returned the correct result, you can always check it using the half life formula.
How many drops of caffeine she drops on the worm is the manipulated variable.
In an experiment, the independent variable is a manipulated variable. Due to the fact that you may alter it, it is termed the "manipulated" one. In other words, you can choose in advance whether to raise it or lower it. Only one variable should be changed at a time throughout an experiment.
The Independent variable is Caffeine's impact. the production and use of nitrogen fertilizers, as well as the burning of fossil fuels in autos, power plants, and industries, are dependent variables that are local in scope. the heart rate of the worm is the responding variable in this experiment.
When an earthworm is given a stimulant like caffeine, its heart rate rises. Does coffee make an earthworm's heart beat faster? is the research topic upon which the experiment is based. The effect of coffee is the independent variable in this research question, and the response it causes is a change in heart rate (the dependent variable) This brings us to the following theory: "If an earthworm is given a stimulant like caffeine, then its heart rate accelerates."
To know more about manipulated variable refer to: brainly.com/question/11505552
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The answer is D because the layers all the way at the bottom had to be there for other layers to be built on top
