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Find the net rate of radiation by a pot at 41.9°C that has been placed in a -24.1°C freezer. The pot's surface area is 0.133m² and its emissivity is 0.683.

User Sandro L
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1 Answer

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Final answer:

The net rate of radiation Q_net from a pot at 41.9°C to a -24.1°C freezer, with a surface area of 0.133m² and emissivity of 0.683, is approximately 2.2662 x 10^7 W.

Step-by-step explanation:

The net rate of radiation can be calculated using the Stefan-Boltzmann Law, which is given by the formula:

Net rate of radiation = ε σ A (T_1^4 - T_2^4)

where:

- ε is the emissivity of the surface,

- σ is the Stefan-Boltzmann constant 5.67 x 10^{-8} W m}^{-2} K^{-4},

- A is the surface area,

- T_1 is the temperature of the warmer object (in Kelvin),

- T_2 is the temperature of the colder object (in Kelvin).

First, we need to convert the temperatures to Kelvin:

T_1 = 273.15 + 41.9 K

T_2 = 273.15 - 24.1 K

Now, we can substitute these values into the formula:

Net rate of radiation = (0.683) x (5.67 x 10^{-8}) x (0.133) x (273.15 + 41.9)^4 - (273.15 - 24.1)^4

Calculating this expression will give you the net rate of radiation.

Let's calculate the net rate of radiation using the provided values:

T_1 = 273.15 + 41.9 K = 315.05 K

T_2 = 273.15 - 24.1 K = 249.05 K

Now, substitute these values into the formula:

Net rate of radiation = (0.683) x (5.67 x 10^{-8}) x (0.133) x (315.05)^4 - (249.05)^4

Calculating this expression will give you the net rate of radiation. Let's compute it:

Net rate of radiation ≈ (0.683) x (5.67 x 10^{-8}) x (0.133) x (315.05)^4 - (249.05)^4

Net rate of radiation ≈ 0.683 x 5.67 x 10^{-8} x 0.133 x (7.169 x10^{14} - 2.552 x 10^{14})

Net rate of radiation ≈ 0.683 x 5.67 x 10^{-8} x 0.133 x 4.617 x 10^{14}

Net rate of radiation} ≈ 2.2662 x 10^7 W

So, the net rate of radiation by the pot is approximately 2.2662 x 10^7 W.

User Chintamani Manjare
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