Answer:
The refrigerator was at around 13 ∘C
Step-by-step explanation:
Newton's Law of Cooling:
The rate of change of a body temperature (amount of heat loss/time of loss) is directly proportional to the difference between its own temperature and the surroundings.
T ⇒ temperature
t ⇒ time
Tenv ⇒refrigerator temperature
⇒ rate of change of he temperature
-h ⇒ constant of proportionality (negative because the temperature is decreasing inside the refrigerator)
We have 3 points:
time (minutes) - Temperature (∘ C)
0 (when the pan was put in the refrigerator) - 46
15 (after 15 minutes) - 27
30 (15 minutes after the first 15 minutes) - 19
= -h (27 - Tenv)
= -h (19 - Tenv)
Now we have a system of two equations and two variables
The refrigerator was at around 13 ∘C
Use Pythagorean thrm
17^2+10^2=21^2
289+100=441
389≠441
This is not a right triangle
Answer:
50-2.5t=w. no, the water will all have drained by then.
Step-by-step explanation:
2.5 per min so
min=t
therefore 2.5t
theres 50 quarts of water
50-2.5t = w (water left in the tank)
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part 2,
2.5*30 = 75, and 50<75
this is impossible.
Answer:
30 students
Step-by-step explanation:
80% of N = 24 where N is the total number of students
So
.80 N = 24
N = 24 / .80 = 30
sorry this was a late response
To minimize the cost, we take the straight distance from the refinery to the other side of the river as 2 km. Also, the 7 km will be the distance that has to be traveled by the pipeline in land. The total cost, C, is therefore,
total cost = (2 km)($800,000/km) + (7 km)($400,000 /km)
total cost = $4,400,000
Thus, the total cost of the pipeline is approximately $4,400,000.00.
