Answer:
t=1.4hours
Explanation:
The half life is 1hour
At t=0 he has a mass of 4kg
So he want it to be 1kg, so that his weapon can work.
Applying the exponential function of decay
M=Cexp(-kt)
Where,
M is the mass at any time
C is a constant of integration
k is the rate of decay
Given that it has an half life of 1 hours.
Then k is 1
At t =0 the mass is 4kg
Therefore
4=Cexp(0)
C=4
M=4exp(-kt)
Since rate of decay is 1, then k=1
M=4exp(-t)
We need to find t at M=1kg
1=4exp(-t)
1=4exp(-t)
1/4=exp(-t)
0.25=exp(-t)
Take In of both sides
In(0.25)=-t
-1.3863=-t
Then, t=1.386hour
Then it will take about 1.4 hours to get to 1kg.
Answer:
3.6 kHz
Explanation:
The pipes behave like a closed pipe . The end open is the end of the air canal outside the ear and the closed end is the eardrum.
The first harmonic will be as seen in the figure attached.
The length of the first harmonic will be λ/4.
λ/4=2.4 cm
λ=2.4 * 4=9.6 cm 0.096 m
Speed of Sound- 344 m/s(in air)
velocity(v) * Time Period(T) = Wavelength (λ)
Also, Time Period(T)= \frac{\textrm{1}}{\textrm{Frequency(f)}}
\frac{\textrm{Velocity}}{\textrm{Wavelength}}=\frac{\textrm{1}}{\textrm{Time Period}} =Frequency
Plugging in the values into the equation,
Frequency = 
Hz
= 3583.3 Hz≈3600 Hz= 3.6 kHz
Frequency= 3.6 kHz
For this we want to use Boyle's Law. Boyle’s law states that the pressure and volume of a fixed quantity of a gas are inversely proportional under constant temperature conditions. The formula for this is P1V1 = P2V2. We want to solve this out so it equals V2 (Volume 2). So P1V1 / P2 = V2. Then plug in your values for the variables. So (101)(4.2) / 235 = V2; so 424.2 / 235 = V2. The final volume equals 1.81. I hope this helps, If not I am very sorry.
Nicolaus Copernicus was the one who brought astronomy out of the dark ages.
In one of his books "On the Revolutions of the Heavenly Bodies", he published the renowned line which declares his theory.
Nicolaus Copernicus, A polish astronomer put forward the theory that the is th Sun one that rests in the middle or center of the Universe and the planet Earth revolves around it on its axis every day.which was considered to be called the Heliocentric system.
To know more about the Heliocentric system refer to the link brainly.com/question/3491738?referrer=searchResults.
To know about Sir Nicolaus Copernicus' work refer to the link brainly.com/question/6699117?referrer=searchResults.
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the answer in my opinion would be A
