3) The embers at the centre of a campfire of radius 15.0 cm emit light with...

Transcribed Image Text:

3) The embers at the centre of a campfire of radius 15.0 cm emit light with a peak wavelength of 2.6 µm. (a) Is this peak wavelength in the visible, infrared, or ultraviolet range of the spectrum? (b) Assuming that the fire behaves as an ideal blackbody, what is the temperature in degrees Celsius at its centre? (c) Calculate the ratio of emitted light intensity for wavelengths of (i) 405 nm and (ii) 755 nm. Can you explain why the fire appears to be red? (d) Assuming the fire behaves as an ideal blackbody, what is the total power of electromagnetic radiation emitted? (Note: because of cooler firewood surrounding the centre, the actual emitted power will likely be less.) (e) If you're standing 14 m from the centre of the fire, how much energy do you absorb per second from the fire? (Note that the ability to make estimates is a very important skill for a physicist: Do you think a medium-size campfire at 14 m would warm you up as much as a nearby 100 W incandescent light bulb?) 3) The embers at the centre of a campfire of radius 15.0 cm emit light with a peak wavelength of 2.6 µm. (a) Is this peak wavelength in the visible, infrared, or ultraviolet range of the spectrum? (b) Assuming that the fire behaves as an ideal blackbody, what is the temperature in degrees Celsius at its centre? (c) Calculate the ratio of emitted light intensity for wavelengths of (i) 405 nm and (ii) 755 nm. Can you explain why the fire appears to be red? (d) Assuming the fire behaves as an ideal blackbody, what is the total power of electromagnetic radiation emitted? (Note: because of cooler firewood surrounding the centre, the actual emitted power will likely be less.) (e) If you're standing 14 m from the centre of the fire, how much energy do you absorb per second from the fire? (Note that the ability to make estimates is a very important skill for a physicist: Do you think a medium-size campfire at 14 m would warm you up as much as a nearby 100 W incandescent light bulb?)