Please need help with both A and B The average human produce

Please need help with both A and B

The average human produces about 15 g of sweat per minute during intense actives. If a jogger runs for 30 mins and evaporates all of the sweat he produces after his run, how much heat was transferred from his body to the sweat? Assume the jogger is always seating, the sweat\'s initial temperature is 37^degreeC, and that sweat has the same specific heat and latent heat as water. A heat stroke occurs when a human\'s body temperature reaches about 40.0^degreeC. If the jogger was not sweating to cool themselves down, how long would it take for a heat stroke to occur? The specific heat of the human body is about 3500 J/(kg K). For simplicities sake, assume the jogger weighs 180 pounds and that the body does not radiate heat out into the surroundings.

Solution

a) Amount of sweat produced in 30 minutes = 15 x 30 = 450 g = 0.45 kg.

Heat needed to evaportate m kg of water (sweat in this case) from T C = mC(100 - T) + mL, where C is specific heat of water and L is latent heat of water.

L = 2265 kJ/kg, C = 4.186 J/g/C

Then, Heat required = 450 x 4.186 x (100 - 37) + 0.45 x 2265 = 118.673 kJ + 1019.25 kJ = 1137.923 kJ.

Therefore 1138 kJ amount of heat should be transferred from body to sweat.

b) Mass of Jogger = 180 pound = 81.65 kg

Amount of heat required to raise temperature from (37 + 273) K to (40 + 273) K = mC x 3 = 81.65 x 3500 x 3 = 857325 J = 857.325 kJ

According to the previous calculation, heat produced per minute = 1138 kj/30 = 37.93 kJ.

TIme taken to produce 857.325 kJ = 857.325/37.93 = 22.6 minutes.

Then for stroke it will take 22.6 minutes.