A mug of tea cools to the law Tt = Toe-kt Where Tt is temperature after t mins and To is inital temperature.
Tt = 75
To = 100
t = 15
giving the equation 75 = 100e-15k
I'm not sure how to take it on from there though.
+1316 Usually it tell you this then it ask a question. What you probably want to do is solve for the k part.
Take the natural log of both sides
\(Ln(75) = Ln(100e^{-15k}) \)
\(Ln(75) = -15k*100\)
\(k= - (Ln(75)/1500)\)
\(k = - 0.0028783254090242\)
+1316 Usually it tell you this then it ask a question. What you probably want to do is solve for the k part.
Take the natural log of both sides
\(Ln(75) = Ln(100e^{-15k}) \)
\(Ln(75) = -15k*100\)
\(k= - (Ln(75)/1500)\)
\(k = - 0.0028783254090242\)
Solve for k over the real numbers:
75 = 100/e^(15 k)
100/e^(15 k) = 100 e^(-15 k):
75 = 100/e^(15 k)
75 = 100/e^(15 k) is equivalent to 100/e^(15 k) = 75:
100/e^(15 k) = 75
Divide both sides by 100:
e^(-15 k) = 3/4
Take reciporicals of both sides:
e^(15 k) = 4/3
Take the natural logarithm of both sides:
15 k = log(4/3)
Divide both sides by 15:
Answer: | k = 1/15 log(4/3)=.0.01917880..........
+129852 That's OK, Dragonlance.....I still gave you 5 points for a good effort....
I'm not always sure about MY answers, either......that "package being thrown from the helicopter" is still bothering me some.....!!!!
+1316 Wow I get 19 points for a wrong answer? CPhill give me 5 so 2 others give me 5 each and one give me 4. And the guest who get it right not get any. Hahaha I not know why that is funny but it is.
My teacher would give me a big fat ZERO for this hog slop. Well maybe he give one point. He not put up with wrong answers much. One time a student was complaining because the teacher give him 1 point on a 10 point question. He put the right number down but he have the wrong sign. So Mr. Addink says ok I’ll put down 10 points then mark the sign so you will have negative 10. Would you prefer that? He not prefer it at all. Hahaha
