Portal: Drought Throughout our lectures, we have leamed that our body\'s primary
ID: 109672 • Letter: P
Question
Portal: Drought Throughout our lectures, we have leamed that our body's primary defense against high temperatures is through sweating (perspiration). Let's consider a 200 lb (91 kg) male farmer in the Central Valley of California on a July day when the air temperature is 110°F (43°C). On this day, the humidity is low enough that all the sweat evaporates from the farmer's skin, enabling him to maintain a body temperature of 100°F (38°C). The farmer sweats 1 liter (1000 g) per hour and 60% of the latent heat needed to evaporate this sweat is provided by farmer's body (the other 40% is provided by the air). If the farmer suddenly dehydrates and stops sweating ow ong will it take for his body temperature to rise to a near-fatal 110°F (43°C)? Please show alloryw. Assumptions you will need to use: It takes 4200 Joules of energy to warm each kilogram (kg) of his body rc (1.8F). The latent heat of vaporization is 2,400,000 Jkg. This valuc means that it takes 2,400,000 Joules energy to convert one kilogram of sweat (a liquid) into a gas 1 . 2. Hint: First calculate how much energy it takes energy his body was giving away when he was sweating at a numbers to find the time! to raise his body from 38 to 43. Then calculate how much when he was sweating at a rate of I-liter/hr (I kg/hr). Use the ratio of these twoExplanation / Answer
Answer- the energy it takes to raise the temperature from 38 to 43 degree celcius
it given that it takes 4200J energy to warm 1kb body by the 1 degree celcius
so the energy take to warm 91kg the 5 degree celcius temperature from 38 to 43 would be = *91*5*4200 = 91*21000J = 1911000
it also given that farmer is sweating at the rate of 1litre per hour. latent heat of evaporization is 2400000J which means it is energy required to comvert 1kg sweat to gas. So amout of energy released in 1L (1000g ) swaeting will be 2400I000J.
So time required to faint the farmer would be the ratio of energy = 1911000/2400000 = 0.79 hours. So the time takes to faint the farmer will be 0.79 hours.