Question

@DanJS

Answer 1

i got 21

Answer 2

k 1 second

Answer 3

I remember solving this differential equation in class, the answer is

T(t) = A + C*e^(k*t)

Where C is a constant

Answer 4

you can separate variables like the last problem

Answer 5

what is T(0)?

Answer 6

A = room temperature = 75
so
T(t) = 75 + C*e^(k*t)

Answer 7

T(0) = 180
T(10) = 100

Answer 8

so

Answer 9

T(0) = 180 = 75 + Ce^0 = 75 + C

180 = 75 + C

C = 180 - 75 = 105

Answer 10

Now we have:

T(t) = 75 + 105*e^(k*t)

Answer 11

Use the next point you have to figure out the k value

Answer 12

T(10) = 100 = 75 + 105e^(k*10)

Answer 13

so k = -0.143508

T(t) = 75 + 105*e^(-0.1435*t)

Answer 14

If you put t=10 in there, you get 100
t= 0 in there , you get 180

Answer 15

How long will it take to cool to 80?

Answer 16

80 = 75 + 105*e^(-0.1435*t)

Answer 17

For T(t) = 80 degrees ; t = 21.22 minutes

Answer 18

lol get all that

Answer 19

So yeah you were right initially, you said 21

Answer 20

hahhaha thanks