Small potato balls of 0.5 cm radius (can be approximated as a sphere) baked in the oven and initially at a uniform temperature of 160°C. Assume, potatoes have a density of 650 kg/m³, specific heat of 3400 J/kgK and conductivity of 1 W/mK. You want to eat potatoes quickly without burning your tongue so that you have decided to cool them down with forced convection. Air h, T. hot potato initially @ T Air temperature is 20°c and the convective heat transfer coefficient is 140 W/m²K. Calculate the time (in seconds) required for its surface temperature to drop 90°C. Round the value you calculated and write it as an integer!!! For example, if you find 8.2, write is as 8..

Small potato balls of 0.5 cm radius (can be approximated as a sphere) baked in the oven and initially at a uniform temperature of 160°C. Assume, potatoes have a density of 650 kg/m³, specific heat of 3400 J/kgK and conductivity of 1 W/mK. You want to eat potatoes quickly without burning your tongue so that you have decided to cool them down with forced convection. Air h, T. hot potato initially @ T Air temperature is 20°c and the convective heat transfer coefficient is 140 W/m²K. Calculate the time (in seconds) required for its surface temperature to drop 90°C. Round the value you calculated and write it as an integer!!! For example, if you find 8.2, write is as 8..

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.18P

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