An iron bar 2.00 cm x 4.00 cm x 11.0 cm at a temperature of 95.0C is dropped into a barrel of water at 25.0C. The barrel is large enough so that the water temperature rises negligibly as the bar cools. The rate at which heat is transferred from the bar to the water is given by the expression Q = UA(Tb-Tw) where U [= 0.050 J/(min cm2 C) is a heat transfer coefficient, A (cm2) is the exposed surface area of the bar, and Tb(C) and Tw(C) are the temperature of the bar and the water temperature, respectively. The heat capacity of the bar is 0.460 J/(gC). Heat conduction in iron is rapid enough for the temperature Th(t) to be considered uniform throughout the bar. You may assume the specific gravity of the bar to be 7.70. Physical Property Tables Energy Balance Which of the following equations accurately represents the energy balance for the bar (p = the density of the bar (g/cm3), V = the volume of the bar (cm3))? VP pvc," -- UAT: -7.) vor = ,1, -1) VpC, UA(1) -T) van -- ,( -T) - (T-1) ) Tw dt dT UACp (T) TW dt dT) = ) - dt - UAC Th - TW V VP dt dT) dt UA Vp To TW Hint Save for Later Attempts: 0 of 1 used Submit Answer Cooling Time Integrate the energy balance, apply the appropriate initial condition, and solve for the time required for the bar to cool to 35.0 C. t = i min