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.
$13 (?) off the original price of 240 is 229. She will have to pay $229.00
Answer:
x=-1
Step-by-step explanation:
x+2-1=0
-1+2=1
1-1=0
y=0
Find the volume of the silo.
The formula is: Volume = PI x r^2 x h
Replace volume with the volume of grain and solve for h:
38000 = 3.14 x 24^2 x h
38000 = 3.14 x 576 x h
38000 = 1808.64 x h
Divide both sides by 1808.64
h = 38000 / 1808.64
h = 21.01
The grain would be 21.01 feet ( round to 21 feet.)
Answer:
-19k ≠ 0
No solutions
Step-by-step explanation:
k/4 - 5k + 1 = 1
4 (k/4 - 5k + 1 = 1)
k-20k + 4 = 4
-19k ≠ 0