Question

One of the means by which humans reject heat from their body is through utilizing

the heat of vaporizing of water (2257.1 kJ/kg of water). We sweat and then, as the water

evaporates, we get the benefit of the latent cooling effect. Turkeys, on the other hand, do not

sweat. So when they get too hot, they explode. To compensate for the turkey’s lack of sweat

glands, one means to still get this latent cooling effect is to spray the turkeys with a fine mist of water. On a certain day, the turkeys must be cooled 10 C in 10 minutes to prevent the mess alluded to above. The average turkey can be assumed to weigh 7 kg and have a specific heat of 2.98 kJ/kg C. What is the rate at which water must be evaporating from the average turkey to prevent it from meeting an untimely demise? Assume that the density and the specific heat of the water is 1000 kg/m3 and 4200 J/kg K.

Answer 1

Solution:

Let V be the Volume of water which evaporates in order to compensate for a rise in temperature of the Turkey,

Therefore, we can write,

so rate at which water evaporates in 10 minutes will be,