You open a case of Cherry Coke from the garage to put cans in the refrigerator. You put the 85°F cans in the 36°F refrigerator. After 5 minutes, the can temperature has gone down to
71°F. Find the constant "k" using Newton's Law of Cooling.

9514 1404 393

  k ≈ -0.06729

Step-by-step explanation:

The initial temperature difference is 85 -36 = 49 degrees. After 5 minutes, the temperature difference is 71 -36 = 35 degrees. The constant k is the natural log of the ratio of these temperature differences, divided by the time unit.

  k = ln(35/49)/5 ≈ -0.06729

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The equation for the temperature T of the can in the refrigerator is ...

  T = 49e^(-0.06729t) +36

Additional comment

Be careful with the sign. If you're filling in k in e^(-kt), then the sign of k will be positive. Above, we have taken the form of the exponential term to be e^(kt), so k is negative.

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11

a=24; b=12

step-by-step explanation:

a/b=2: 1

a=2b

36/(1+2)=12

b=12

a=24