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One suggested treatment for a person who has suffered a stroke is to immerse the

ID: 1700618 • Letter: O

Question

One suggested treatment for a person who has suffered a stroke is to immerse the patient in an ice-water bath at 0 to lower the body temperature, which prevents damage to the brain. In one set of tests, patients were cooled until their internal temperature reached 32.1.

To treat a 67.5 patient, what is the minimum amount of ice (at 0 ) that you need in the bath so that its temperature remains at 0 ? The specific heat capacity of the human body is 3480 , and recall that normal body temperature is 37.0.

Explanation / Answer

If the maximum temperature of bath must remain at 0 0C, the ice could just be melt.

heat recieved by ice in melting = heat given by body

mice * Lice   = mpatient * cpatient * (Tinitial  - Tfinal)

latent heat of fusion of ice   Lice = 3.34 * 105  J/kg

mass of patient mpatient    = 67.5 kg

specific heat of patient cpatient   = 3480 J/kg

Initial body temperature Tinitial   = 37.0 0C

Final temperature of body Tfinal = 32.1 0C

mice  * 3.34 * 105   = 67.5 * 3480 * (37.0 * 32.1)

required mass of ice mice   = 11.51 * 105 / 3.34 * 105

= 3.446 kg