The human eye can respond to as little as 10^-18j of light energy. for a wavelength at the peak of visual sensitivity, 550 nm, how many photons lead to an observable flash?

Approximately 3 photons

Explanation:

The energy of a photon at the peak of visual sensitivity is given by:

where

h is the Planck constant

c is the speed of light

is the wavelength of the photon

Substituting into the formula,

This is the energy of one photon. The human eye can detect an amount of energy of

So the amount of photons contained in this energy is

so approximately 3 photons.

which statement about this sum is true? −245+2.7

explanation:

the masses of the objects and the distance between them