Question

Before going in for an annual physical, a 70.0-{\rm kg} person whose body temperature is 37.0{\rm ^{\circ} C} consumes an entire 0.355-{\rm liter} can of a soft drink (which is mostly water) at12.0{\rm ^{\circ} C}.
A.)What will be the person's body temperature T_final after equilibrium is attained? Ignore any heating by theperson's metabolism. The specific heat capacity of a human body is3480 {\rm J/kg \cdot K} .

B.)Is the change in the person's body temperature great enoughto be measured by a medical thermometer? (A high-quality medicalthermometer can measure temperature changes as small as0.1{\rm ^{\circ}C} or less.) yes or no

Answer 1

Answer:

A) The person's body temperature T_final after equilibrium is attained = 36.85°C

B) The change in the person's temperature after equilibrium is attained = 0.15°C

A high-quality medical thermometer can measure temperature changes as small as 0.1°C, hence, YES, it would detect the minute drop by 0.15°C too.

Explanation:

If we assume that the soft drink has the same density as water (since it is stated in the question that it is mostly water).

Density of water = 1 g/mL = 1 kg/L

Ignoring any heating by the person's metabolism,

A) So, heat lost by the human body = heat gained by the soft drink as it attains thermal equilibrium with the human body

Let the final temperature of the human body + soft drink set up be T

Heat lost by the human body = mCΔT

m = mass of the human body = 70.0 kg

C = Specific heat capacity of the human body = 3480 J/kg.K

ΔT = Temperature change of the human body = 37 - (Final temperature) = 37 - T

Heat lost by the body = 70 × 3480 × (37 - T)

= (9,013,200 - 243,600T) J

Heat gained by soft drink = mCΔT

m = mass of the soft drink = density × volume = 1 × 0.355 = 0.355 kg

C = specific heat capacity of the soft drink = specific heat capacity of the soft drink = 4182 J/kg.K

ΔT = (final temperature) - 12 = (T - 12)

Heat gained by the soft drink = 0.355 × 4182 × (T - 12) = (1,484.61T - 17,815.32) J

heat lost by the human body = heat gained by the soft drink as it attains thermal equilibrium with the human body

(9,013,200 - 243,600T) = (1,484.61T - 17,815.32)

9,013,200 + 17,815.32 = 1,484.61T + 243,600T

9,031,015.32 = 245,084.61T

T = (9,031,015.32/245,084.61)

= 36.8485614825 = 36.85°C

B) The change in the person's temperature = 37 - 36.85 = 0.15°C

A high-quality medical thermometer can measure temperature changes as small as 0.1°C, hence it would detect the minute drop by 0.15°C too.

Hope this Helps!!!