Question

As 390-g of hot milk cools in a mug, it transfers 30,000 J of heat to the environment.

How does the temperature of the milk change? (cmilk = 3.9 J/g°C)


It decreases by 77°C.
It decreases by 20°C.
It increases by 77°C.
It increases by 20°C

Answer 1

@anyone

Answer 2

@hartnn

Answer 3

@pig_cat223

Answer 4

hang on and ill try i gotta problem of my own...

Answer 5

ok

Answer 6

Hmmm

Answer 7

anyone know??

Answer 8

im sorry but i have no idea what is, i dont even know where to start and i cant find anything online either.... sorry and thanks for the help on mine... :D

Answer 9

np

Answer 10

:/

Answer 11

know of anyone who can help???

Answer 12

i tried asking for you in the math chat box but they were typing to fast to see it.... but you should ask

Answer 13

ok

Answer 14

@Episode

Answer 15

We can apply Newton's Law of cooling yes?

Answer 16

yes?

Answer 17

I am not that good at this

Answer 18

Do you know calculus?

Answer 19

not that well

Answer 20

been 3 years since i did it last so very rusty

Answer 21

This is specific heat

Answer 22

So I guess we don't really need calculus we can apply the formula you had earlier, \[Q = c m \Delta T \implies \Delta T = \frac{ Q }{ cm }\] since delta t is the change in temperature

Answer 23

That will give you your result :)

Answer 24

ok

Answer 25

remember c is the specific heat, and m is the mass

Answer 26

Q is change in temp

Answer 27

so can you help me plug it in

Answer 28

Try plugging it in yourself and I will tell you if you're right or not

Answer 29

thing is not sure what is what

Answer 30

this is why i am asking for u to help please

Answer 31

You have the formula and variables read your question carefully and try, and I will show you the right answer after

Answer 32

^T=30000/390(30000) ????

Answer 33

Like i said I am not good with this i think it got this wrong

Answer 34

Careful, \[\Delta T = \frac{ 30,000 J }{ (3.9)(390g)}\] If you plug in all the units you will see, you get the temperature

Answer 35

You almost had it right, you put Q again instead of the specific heat

Answer 36

\[DeltaT=30000/(3.9)(390)=3,000,000\]

Answer 37

am i right?

Answer 38

Nope, plug it in your calculator

Answer 39

hold on

Answer 40

same answer what am i doing wrong

Answer 41

You're dividing right? 30,000J by 3.9*390

Answer 42

yes

Answer 43

Then you should get 19.7 degrees

Answer 44

hey @AndrewKaiser333

\[q = m~C~\Delta T \]

Answer 45

i see what i did now. thanks

Answer 46

Yw :)

Answer 47

so increases by 20°

Answer 48

Right

Answer 49

thanks this helps alot

Answer 50

Yes, that is what we applied @Photon336 if you scroll up a bit

Answer 51

energy is lost to the environment. q,

\[\frac{ -30,000J }{ 390G*3.9Jg^{-1}c^{-1}} = \Delta T \]

Answer 52

@episode heat is lost to the environment so I'm guessing that Q would be negative

Answer 53

Yes, you are right, I did not read that part! Good catch @Photon336

Answer 54

@AndrewKaiser333
As photon mentioned the mug would cool, so the temperature would decrease

Answer 55

Yeah that's one of those things I get confused by and as @Episode said that's important because that will show you how the temperature would change.

Cheers guys

Answer 56

Thanks @Photon336 :)