Answer:
9 hours
Step-by-step explanation:
According to Newton's laws of cooling
dT/dt = -k(T - A)
Let U = T - A
dU/dT = 1
dU = dT
dt/dt = -kU
dT = -kU(dt)
dU/U = -kdt
On integration
ln(U) = -kt + C
U = Ce^-kt
T - A = Ce^-kt
T(0) = 68
T(5) = 25
68 - 20 = Ce^-k(0)
C = 48
and
25 -20 = 48e^-k(5)
5 = 48e^-5k
e^-5k = 5/48
-5k = ln (5/48)
k = - ln(5/48) / 5
k = - 0.4524
T - 20 = 48e^-0.4524t
When T = 21
21 -20 = 48e^-0.4524t
1 = 48e^-0..4524t
e^-0.4524t = 1/48
-0.4524t = ln (1/48)
t = - ln(1/48) / 0.4524
t = 8.5570
t= 9 hours ( to the nearest hour)
Answer:
97
Step-by-step explanation:
Add the sides of the triangle,
44 + 39 = 83
There needs to be 180 degrees in a triangle,
180 - 83 = 97
The remaining side is 97 degrees which is side h
Answer:
x = 9.1
Step-by-step explanation:
x^2 + 16^2 = 18.4^2
x^2 + 256 = 338.56
x^2 = 82.56
x = 9.1
Answer:
3x+2y+2=0
3x=-2y-2
x=-(2y+2)/3
Step-by-step explanation:
Answer:
1,050
Step-by-step explanation:
If 15 people out of 50 liked strawberry best.
The relative frequency of liking strawberry best in Sam's hometown will be:
Relative Frequency = 
Expected Outcome=Relative Frequency X Number of Trials
Therefore, out of the 3500 residents:
Number of People Expected to like strawberry best
= 
=1,050
