$20$ points $-$ Compute the steady heat transfer by forced flow of $20C$ air at $4\frac{m}{s}$ speed over a copper sphere of $5$ cm in diameter with $80C$ isothermal surface temperature $($initial temperature$).$ Use the properties of air in the given table in the textbook. Compute the Nusselt number using the formula by Whitaker. Also, use either the lump model or spatial model to get the temperature of the sphere surface $($you must check the Biot number$).$