Complete Question
The complete question is shown on the first uploaded image
Answer:
The time taken is 
Explanation:
From the question we are told that
The value of 
The the interior temperature is 
The external temperature is 
The required interior temperature is 
The newton cooling law is

=> 
Now integrate both sides we have

Since c is a constant lnC = c will also give a constant so
=>
=>
substituting value


Hence


=> 

Slope of a curve Y plotted against X is mathematically given as

now here we can see that if similarly graph is plotted against distance and time then slope is given as

here we can say that above is ratio of small distance and very small interval of time.
so here we can say that this ratio of distance and time for very small interval of time is known as instantaneous speed of the object which is falling freely under gravity.
So here slope of the graph will represent the speed at a given instant.
Answer:
A half-life is the time required for one half of the nuclei in a radio- active isotope to decay.
Explanation:
A radio-active isotope is an isotope which undergoes radioactive decay.
Radioactive decay is a spontaneous process in which the nucleus of an atom changes its state (turning into a different nucleus, or de-exciting), emitting radiation, which can be of three different types: alpha, beta or gamma.
The half-life of a radio-active isotope is the time required for half of the nuclei of the initial sample to decay.
The law of radio-active decay can be expressed as follows:

where
N(t) is the number of undecayed nuclei left at time t
N0 is the initial number of nuclei
t is the time
is the half-life
We see that when
(that means, when 1 half-life has passed), the number of undecayed nuclei left is

So, half of the initial nuclei.
Answer:
i think its B
Explanation:
i found the answer on another website hope its the right answer :)
False, it does create pollution form the smoke stacks and after the process is done they have barrels of toxic waste