A regular light bulb emits electromagnetic waves of variouswavelengths (which makes the âwhiteâ light); in fact thedistribution of intensities is a continuous function of thewavelength (as in discussion of black body radiation). Thisdistribution, however, peaks at some characteristic wavelength. Inthe following assume that the entire power of the light bulb comesfrom emitting in this single characteristic wavelength. A lightbulb has power P=100W.
a) What is the intensity of the emitted light at a distance r=10mfrom the light bulb?
b) What is the amplitude of the electromagnetic field at thatdistance?
c) What is the average energy density of e.m. radiation at thedistance r=10m from
the light bulb.
d) What is the momentum transferred by this light to a small flatmirror with surface
area S=0.5m2 placed in front of the light bulb at the distancer=10m during the
time t=1s.
e) What it the pressure excreted by the light on the surface inpart d)
A regular light bulb emits electromagnetic waves of variouswavelengths (which makes the âwhiteâ light); in fact thedistribution of intensities is a continuous function of thewavelength (as in discussion of black body radiation). Thisdistribution, however, peaks at some characteristic wavelength. Inthe following assume that the entire power of the light bulb comesfrom emitting in this single characteristic wavelength. A lightbulb has power P=100W.
a) What is the intensity of the emitted light at a distance r=10mfrom the light bulb?
b) What is the amplitude of the electromagnetic field at thatdistance?
c) What is the average energy density of e.m. radiation at thedistance r=10m from
the light bulb.
d) What is the momentum transferred by this light to a small flatmirror with surface
area S=0.5m2 placed in front of the light bulb at the distancer=10m during the
time t=1s.
e) What it the pressure excreted by the light on the surface inpart d)
