A copper cube with sides o flength 20 mm had its surface blackened. The cube is heated up to 500K and placed inside a room at a constant temperature of 300K. Calculate the initial rate of temperature fall of the cube, assuming it as a perfect black-body. (Stefan's constant `= 5.7 xx 10^(-8) W//m(2) //K^(4)` specific heat capacity of aluminium `= 400 J //kg//K`, density of aluminium `= 7800 kg//m^(3)` ) where A is the surface area of the cube, `T_(1)` is the temperature of the body, and `T_(2)` is the temperature of the enclosure.

Explanation

To solve the problem of calculating the initial rate of temperature fall of a blackened copper cube placed in a room, we will follow these steps:

### Step 1: Calculate the Surface Area of the Cube
The surface area \( A \) of a cube is given by the formula:
\[ A = 6a^2 \]
where \( a \) is the length of a side of the cube.
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