Answer:
1.33 x 10^26 photons
Explanation:
λ = 12 cm = 0.12 m
Δ T = 5 degree C
m = 11 g = 0.011 kg
c = 4 J/g K = 4000 J / kg K
Let the number of photons are n.
Energy of one photon = h c / λ
Where, h is the Plank's constant and c be the velocity of light.
Energy of n photons, E = n h c / λ
This energy is used to raise the temperature of eye, so
n h c / λ = m c Δ T
n = m c Δ T λ / h c
n = (0.011 x 4000 x 5 x 0.12) / (6.63 x 10^-34 x 3 x 10^8)
n = 1.33 x 10^26
Thus, there are 1.33 x 10^26 photons.
