Daniel Rocha wrote:
I am someone who sincerely want to understand what is happening. If that were my point of view, I would not come here. It seems you people are knowledge able, so I want your opinion.
That's fine. You are not "GoatGuy." It is okay to cross-post that message. I think Esa Ruoho was out of line criticizing you.
However, this estimate of only 150 W for 3 m of black hose that is too hot to touch is completely incorrect. I do not know where his equation is wrong, but I am certain it is wrong. The heat from a 150 W incandescent light spread over an area as large as a 3 m black hose is barely sensible.
There are no units in his equations. I often accidentally drop one or two orders of magnitude when doing arithmetic. To avoid that I recommend you keep the units in all equations. I see one mistake right here. He says the inner diameter (ID) is 1.25 cm. He estimates the outer diameter (OD) at 0.0037 m. That's 0.37 cm. I think he meant 3.7 cm, an order of magnitude more. He figures 1 m of hose has 0.051 square units of surface, which I guess are supposed to be square meters. Anyway, I get 0.24 m^2. Pretty sure that's right.
In equations and scientific papers, always include units! - Jed
