00:01
In the following question, we are required to find out a graph which will show the relationship between theta and the time.
00:08
So, theta is the temperature here and time, which is small t, is on the, we'll be taking that on the y x -axis, whereas theta, which is a temperature on the y -axis.
00:21
So initially here in this case, we'll be using the newton's law of cooling.
00:27
So according to the newton's law of cooling, we know that d theta, which is change in temperature upon dt, which is change in time, will be equal to minus k, a constant into theta minus theta not.
00:49
So this is a relation which was given by newton and this is also known as the newton's law of cooling.
00:56
So further we will be integrating this to make an equation from which we can then plot graphs between temperature and time.
01:05
So d theta will be equal to k theta minus theta not into d t and we'll bring this down over here.
01:18
So d theta upon theta minus theta not will be equal to minus k d tt.
01:28
Now we can integrate both the sides and from this we will get the equation as ln, theta final minus theta not upon theta initial minus theta not, which will be equal to minus kt.
01:51
Furthermore, we can, in order to remove the log, we'll have to take exponent e raised to the power minus kt over here...