Question

The eyes of certain reptiles pass a single visual signal to the brain when the visual receptors are struck by photons of a wavelength of 850 nm. If a total energy of 3.15 × 10^(-14) J is required to trip the signal, what is the minimum number of photons that must strike the receptor?

a) Minimum number of photons
b) Wavelength of photons
c) Total energy required
d) Type of reptile

Answer 1

To find the minimum number of photons needed to trip the receptor, first, calculate the energy of one photon with the given wavelength of 850 nm, then divide the total energy by the energy per photon.

Step-by-step explanation:

The student has asked how many photons with a wavelength of 850 nm must strike a receptor to trip a signal with a total energy requirement of 3.15 × 10-14 J. To calculate this, first, we need to determine the energy of a single photon using the Planck-Einstein relation which connects energy (E) and wavelength (λ) through the equation E = hc/λ, where h is Planck’s constant (6.626 × 10-34 m2kg/s) and c is the speed of light (3 × 108 m/s).

The wavelength of 850 nm must be converted into meters (850 nm = 850 × 10-9 m). We can then find the energy of one photon and divide the total energy required by the energy of one photon to determine the minimum number of photons needed.