3.745 x [tex]10^{-19}J[/tex] is the minimum energy needed to eject electrons from a metal with a threshold frequency of 5.65 x [tex]10^{14}s^{-1}[/tex]
The minimum frequency needed to cause electron ejection is referred to as the threshold frequency.
The energy carried by the incident light is E=hf
Where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
E=hf
h=6.63 x [tex]10^{-34}Js[/tex]
f=5.65 x [tex]10^{14}s^{-1}[/tex]
E=6.63 x [tex]10^{-34}Js[/tex] x 5.65 x [tex]10^{14}s^{-1}[/tex]
E= 3.745 x [tex]10^{-19}J[/tex]
Thus, 3.745 x [tex]10^{-19}J[/tex] is the minimum energy needed to eject electrons from a metal with a threshold frequency of 5.65 x [tex]10^{14}s^{-1}[/tex]
Learn more about threshold frequency here:
https://brainly.com/question/9172394
#SPJ4