To solve this problem we need to take the 450g and multiply it by 4.5 (as it is 4.5 times the amount of the original recipe. 450x4+225 is the easiest way to do the math and your minced beef equals out to 2025g and your answer!

4 0

3 years ago

the temperature of a cup of coffee obeys newton's law of cooling. The initial temperature of the coffee is 150F and 1 minute lat

natka813 [3]

Answer:

Newton's law of cooling says that:

T(t) = Tₐ + (T₀ - Tₐ)*e^(k*t)

or:

$\frac{dT}{dt} = -k*(T - T_a)$

in the differential form.

where:

T is the temperature as a function of time

Tₐ is the ambient temperature, in this case, 70F

T₀ is the initial temperature of the object, in this case, 150F

k is a constant, and we want to find the value of k.

Then our equation is:

T = 70F + (150F - 70F)*e^(k*t)

Now we also know that after a minute, or 60 seconds, the temperature was 135F

then:

135F = 70F + (150F - 70F)*e^(k*60s)

We can solve this for k:

135F = 70F + 80F*e^(k*60s)

135F - 70F = 80F*e^(k*60s)

65F = 80F*e^(k*60s)

(65/80) = e^(k*60s)

Now we can apply the Ln(x) function to both sides to get:

Ln(65/80) = Ln(e^(k*60s))

Ln(65/80) = k*60s

Ln(65/80)/60s = k = -0.0035 s^-1

Then the differential equation is:

$\frac{dT}{dt} = -0.0035 s^-1*(T - 70F)$

8 0

3 years ago