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
I would substitute y = x^2
4y^2 -21y+20=0
It is a function because each x value only has one y value
Answer:
Table, Formula
Step-by-step explanation:
Answer:
Daniel (now) is 3 years old, (2 years ago) is 1 year old.
Kevin (now) is 6 years old, (2 years ago) is 4 years old.
Step-by-step explanation:
Now:
-Kevin: k = d + 3
-Daniel: d
2 years ago:
-Kevin: k - 2 = 4(d - 2)
-Daniel: d - 2
We have the equation:
(k - 2) + 2 = k
4(d - 2) + 2 = d + 3
4d - 8 + 2 = d + 3
3d - 6 = 3
3d = 9
d = 3
k = d + 3 = 3 + 3 = 6