Question

Newton's law of cooling?

Answer 1

I need help with this question.. but could someone also provide a general strategy to answer these kinds of questions?

Answer 2

Newton's law is mathematically stated by the simple first-order differential equation:

\frac{d Q}{d t} = h \cdot A( T_{\text{env}}- T(t)) = - h \cdot A \Delta T(t)\quad

Q= Thermal energy in joules
h= Heat transfer coefficient
A= Surface area of the heat being transferred
T = Temperature of the object's surface and interior (since these are the same in this approximation)
T_{\text{env}} = Temperature of the environment
\Delta T(t)= T(t) - T_{\text{env}} is the time-dependent thermal gradient between environment and object

Putting heat transfers into this form is sometimes not a very good approximation, depending on ratios of heat conductances in the system. If the differences are not large, an accurate formulation of heat transfers in the system may require analysis of heat flow based on the (transient) heat transfer equation in nonhomogeneous, or poorly conductive media.

Answer 3

right.... and in english?

Answer 4

\[\frac{\text dT}{\text dt}=k\left[T-T_m\right]\]
\[T-T_m=ce^{kt}\]

Answer 5

Porque no hablas espanol?