I am finding a difficult time find out what sort of formula to use in this equation and how to approach it$.$

A cast$-$iron ball $20$ cm in diameter is heat$-$treated in a radiant oven to

harden it$.$ The heating elements operate at $1300\backslash$deg C and the ball temperature is

raised from $20\backslash$deg C to $727\backslash$deg C$.$ Take the specefic heat of $0\mathrm{.}544$ and density of $7\mathrm{.}21$ and the emissivity of cast iron as $0\mathrm{.}75.$

$($a$)$ How much heat does the cast iron absorb per second when inserted into

the oven at $20\backslash$deg C$?(32\mathrm{.}68$ kJ$/$s$)$