19-1 REDO

A. laser pulse with a wavelength of 545nm contains 4.40mJ of energy. How many photons are in the laser pulse? Express the number of photons to three significant figures. formard.A Wido for Part. redo folpart A reletior Part A keyboard shortcuts for Part A help for Part A. N= photons * Incorrect; Try Again; 16 attempts remaining To solve the problem, first calculate the energy of a photon from its wavelength. You can use dimensional analysis to keep track of units given that Plank's constant has the units J/s and the speed of light has the units m/s. You want units to cancel out, leaving you with units of J for the energy of a single photon. Once you have the energy for a single photon, calculate the number of photons by dividing the total energy of the pulse, which is the energy of all the photons in the pulse, by the energy of an individual photon. You may want to review