CLIMATE 105: Our Changing Atmosphere (Spring 2024)
Assignment 2
Due Friday, May 24: please show all work!
1.
Calculate the energy of photons with the following wavelengths: (10 points)
E =
ℎ𝑐
λ
(Planck’s constant, h = 6.626 × 10
-34
m
2
kg/s; velocity of light, c = 3 x 10
8
m/s)
a.
1 m
E = (6.626 x 10
-34
x 3 x 10
8
/ 1) J
E = 1.987 x 10
-25
J
b.
1 cm
E = (6.626 x 10
-34
x 3 x 10
8
/ 1) J
E = 1.987 x 10
-23
J
c.
0.5 μm
E = (6.626 x 10
-34
x 3 x 10
8
/ 0.5 x 10
-6
) J
E = 3.975 x 10
-19
J
d.
250 nm
E = (6.626 x 10
-34
x 3 x 10
8
/ 250 x 10
-9
) J
E = 7.951 x 10
-19
J
2.
Calculate the energy flux and peak wavelengths of the energy radiated from the
following celestial objects: (10 points)
𝐹
=
𝜎 𝑇
4
λ = 2989
𝑇
(Stefan – Boltzmann constant, σ = 5.67 × 10
−
8
W m
−
2
K
−
4
;
a.
The Sun’s photosphere or “surface”: T = 5700 K
F = (5.67 × 10
−8
x 5700
4
) W/m
2
F = 59852525.67 W/m
2
= 5.985 x 10
7
W/m
2
λ
max
= (2898 / 5700) μm
λ
max
= 0.508 μm
b.
Neutron star: T = 600,000 K
