Answer:
Explanation:
Energy of a photon = hν , h is plank's constant and ν is frequency .
= h c / λ ; c is velocity of light and λ is wavelength .
= 6.6 x 10⁻³⁴ x 3 x 10⁸ / 550 x 10⁻⁹
= .036 x 10⁻¹⁷ J
Let no of photons be n .
Total energy of n photons
= n x .036 x 10⁻¹⁷ J
Intensity of light = 5 x 10⁻¹² J /m²
Total energy flowing through eye per second
= intensity x area of eye.
= 5 x 10⁻¹² x π x .2² x 10⁻⁴
= .628 x 10⁻¹⁶ J
so
n x .036 x 10⁻¹⁷ = .628 x 10⁻¹⁶
n = .628 x 10⁻¹⁶ / .036 x 10⁻¹⁷
= 17.36 x 10
= 173.6
174.
