Answer:
energy is 36 mJ
radiation pressure exerted by the beam is 1.9254 × [tex]10^{-6}[/tex] Pa
Explanation:
Given data
diameter = 2.3 mm = 2.3 × [tex]10^{-3}[/tex] m
power = 2.4 mW = 2.4 × [tex]10^{-3}[/tex] J/s
time = 15 s
to find out
energy and radiation pressure exerted
solution
we know for energy
that is energy = power × time
energy = 2.4 × [tex]10^{-3}[/tex] × 15
energy = 36 × [tex]10^{-3}[/tex] J
so energy is 36 mJ
and
now first we find cross section area that i s
cross section Area A = πd²/4
A = π(2.3 × [tex]10^{-3}[/tex])²/4
A = 4.155 × [tex]10^{-6}[/tex] m²
and intensity of radiation will be power / area
so intensity of radiation = 2.4 × [tex]10^{-3}[/tex] / 4.155 × [tex]10^{-6}[/tex]
intensity of radiation = 577.62 W/m²
so that now for radiation pressure for beam that is
pressure = intensity of radiation / speed of light
we know speed of light is 3 × [tex]10^{8}[/tex] m/s
so
pressure = 577.62 / 3 × [tex]10^{8}[/tex]
pressure = 1.9254 × [tex]10^{-6}[/tex] Pa
so radiation pressure exerted by the beam is 1.9254 × [tex]10^{-6}[/tex] Pa
