Answer:
(b) 67
Step-by-step explanation:
A solution to the differential equation describing the temperature according to Newton's Law of Cooling could be written as ...
T = (final temp) + (initial difference)×(decay factor)^t
where the decay factor is the fraction of change during 1 unit of time period t.
__
Here, the initial difference of 100-25 = 75 degrees decays to 90-25 = 65 degrees in 1 minute. So, the units of t are minutes, the decay factor is 65/75, the initial difference is 75 degrees, and the final temperature is 25 degrees. That lets us write the equation as ...
T = 25 +75(65/75)^t
Then for t=4, the temperature is ...
T = 25 +75(13/15)^4 ≈ 67.3 . . . . degrees
After 4 minutes the temperature of the coffee is about 67 degrees.
The sides, so the surface area
that is square meters
B is answer
Answer:
Slope: m = 0
Equation: y = 3
Step-by-step explanation:
The equation of a line has the following format:

In which m is the slope.
We choose two points which the equation crosses.
I am going to choose (0,3) and (1,3)
(0,3)
When x = 0, y = 3. So



(1,3)
When x = 1, y = 3. So



Slope: m = 0
Equation: y = 3