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.
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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.
Answer:
an example of a ratio as a fraction in its simplest form is .5 is 1: 2.
Answer:
Step-by-step explanation:
16-2t=t+9+4t
7=7t
t=1
Step-by-step explanation:
The Midpoint Formula works exactly the same way. If you need to find the point that is exactly halfway between two given points, just average the x-values and the y-values.
Answer:
X = - 5
Step-by-step explanation:
The above word problem is mathematically interpreted thus:
-1X - 4X = -4 - 4X + 4 + 5
-5X = - 4 - 4X + 4 + 5
-5X = - 4 - 4X + 9
Collect like terms
-5X + 4X = - 4+ 9
-X = 5
X = - 5