Newton's Law of Cooling states that the change
of the temperature of an object is proportional to the difference between its
own temperature and the ambient temperature over time.
Therefore when expressed mathematically, this is equivalent
to:
dT = - k (T – Ts) dt
dT / (T – Ts) = - k dt
Integrating:
ln [(T2– Ts) / (T1– Ts)] = - k (t2 – t1)
Before we plug in the values, let us first convert the
temperatures into absolute values R (rankine) by adding 460.
R = ˚F + 460
T1 = 200 + 460 = 660 R
Ts = 70 + 460 = 530 R
ln [(T2– 530) / (660 – 530)] = - 0.6 (2 - 0)
T2 = 569.16 R
T2 = 109 ºF
Answer: After 2 hours, it will be 109 ºF
The correct question is
<span>Zach keeps his pet chameleon Pinky in a terrarium with the dimensions 8 x 20. There are three inches of sand in the bottom of the terrarium. Zach gets a new terrarium that is larger. The base of the new terrarium is 10 x 24 inches. Zach moved the existing sand to the new terrarium. How deep will the sand be in the new terrarium?
</span>
Step 1
find the volume of sand
volume of sand=8*20*3------------>Volume of sand=480 in³
Volume of sand in the new terrarium=10*24*h
where h------------> is the deep in the new terrarium
remember that the volume of sand is the same
so
10*24*h=480----------> h=480/(10*24)-----------> h=2 in
the answer is 2 in
Since you can spend all but 20%, then you can spend the rest, namely the 80%.
whatever% of anything is just (whatever/100) * anything.
therefore, 80% of 225 is then (80/100) * 225, that much.
to find the unit rate/constant of proportionality , you'd have to dive 250 by three. and they are related because they are the same thing.
