Heat transfer Question Given a too hot to taste spoonful of

Heat transfer Question:

Given a too hot to taste spoonful of soup. Will the soup temperature decrease faster (as compared to forced convection), if it is allowed to cool solely under the effects of natural convection? yes , or no / why, or why not?

a) yes/ since the thermal conductivity of the soup is greater at higher temperatures

b) yes/ since the viscosity of the soup is lower at higher temperatures

c) no/ since the convective heat transfer coefficient of the air increases as the air velocity is increased

d) no /since the specific heat of the air is greater as the air velocity increases

e) could be either yes or no depending upon the flow regime, as characterized by the Reynolds Number

b yes isme the wiscsity of the o.is lower at righe temera res cl no s1ncethe convastve he transter costticient st the alr increases as the ar velccityis ncrease d; rolaih sa.ilit heal eathz air acctvincoases

Solution

e)could be either yes or no depending upon the flow regime, as characterized by the reynolds number