PHYSICS · Single correct · AP · Physics 2: Algebra-based · Modern Physics · Modern Physics
Problem
A human body has a surface area of approximately 1 m2. The normal body temperature is 10 K above the surrounding room temperature T0. Take the room temperature to be T0=300 K. For T0=300 K, the value of σT04=460 Wm−2 (where σ is the Stefan-Boltzmann constant). Which of the following options is/are correct? [Adv. 2017]
(1) The amount of energy radiated by the body in 1 second is close to 60 joules
(2) If the surrounding temperature reduces by a small amount ΔT0≪T0, then to maintain the same body temperature the same (living) human being needs to radiate ΔW=4σT03ΔT0 more energy per unit time
(3) Reducing the exposed surface area of the body (e.g. by curling up) allows humans to maintain the same body temperature while reducing the energy lost by radiation
(4) If the body temperature rises significantly then the peak in the spectrum of electromagnetic radiation emitted by the body would shift to longer wavelengths