Calculating Heat from Radiation on Metal Object

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Homework Statement



How do I calculate how hot a metal object will get if it's just left to be heated up by the sun?

Homework Equations



The two equations that i know of would be the specific heat capacity of the metal: Q = mCpΔT
And the radiation equation: Q=εσAT^4

The Attempt at a Solution



Do i need to find the total sunlight hitting it per hour?
 
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You need to know the rate of heat loss
If you assume it is perfectly insulated and the only loss is by radiation, then if you assume it's a blackbody (and know it's reflectivity) then you can calculate the final temperature.

Input heat is a function of the source temperature and the area of the metal facing the source.
Output heat is a function of the temperature of the metal and the total area
Temperature at a particular will depend on the mass of the metal, it's heat capacity and the power difference.
But the final temperature will depend only on the area and the source/sink temperature.
 
Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
The value of H equals ## 10^{3}## in natural units, According to : https://en.wikipedia.org/wiki/Natural_units, ## t \sim 10^{-21} sec = 10^{21} Hz ##, and since ## \text{GeV} \sim 10^{24} \text{Hz } ##, ## GeV \sim 10^{24} \times 10^{-21} = 10^3 ## in natural units. So is this conversion correct? Also in the above formula, can I convert H to that natural units , since it’s a constant, while keeping k in Hz ?

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