The maximum energy of the photoelectrons when light of frequency 1.5 x 10^15 Hz is directed on a copper surface is approximately 0.62 eV.
The maximum energy of the photoelectrons can be found using the equation E=hf, where E is the energy, h is Planck's constant (6.63 x 10^-34 J·s), and f is the frequency of the light. To find the maximum energy of the photoelectrons when light of frequency 1.5 x 10^15 Hz is directed on a copper surface, we can substitute the values into the equation:
E = (6.63 x 10^-34 J·s)(1.5 x 10^15 Hz)
Calculating this, we find that the maximum energy of the photoelectrons is approximately 9.94 x 10^-19 J, or 0.62 eV (electronvolts) when rounded to two decimal places.