I'm doing something wrong

[SOLVED] I'm doing something wrong...

1. A red laser with a wavelength of 650 nm and a blue laser with a wavelength of 450 nn emit laser beams with the same light power. How do their rates of photon emission compare? Answer this by computing R$$_{red}$$ / R$$_{blue}$$

2. P = Rhf = dNhf / dt = dE$$_{light}$$ / dt
R = dN / dt
E$$_{light}$$ = Nhf, where N is the number of photons
f = c / $$\lambda$$
h = 6.624E-32 Js

3. I have the f$$_{red}$$ = 4.62 x 10$$^{14}$$ s
and f$$_{blue}$$ = 6.67 x 10$$^{14}$$ s , it says their Powers are the same, so I go ahead and went and equaled:

P$$_{red}$$ to P$$_{blue}$$, which is:

P$$_{red}$$h$$_{red}$$f$$_{red}$$ = P$$_{blue}$$h$$_{blue}$$f$$_{blue}$$

but I am tired and can't see the relevance, because when I multiplied times h [in Js] and then I divide like explained, I get .6925, and the ANSWER is 1.44.

berkeman
Mentor
Since red photons carry less energy per photon, there will need to be more of them. You just got your answer upside-down.

Just use your equation for E = Nhf, and be sure to take the ratio in the correct direction.

Chi Meson
Homework Helper
1. A red laser with a wavelength of 650 nm and a blue laser with a wavelength of 450 nn emit laser beams with the same light power. How do their rates of photon emission compare? Answer this by computing R$$_{red}$$ / R$$_{blue}$$

2. P = Rhf = dNhf / dt = dE$$_{light}$$ / dt
R = dN / dt
E$$_{light}$$ = Nhf, where N is the number of photons
f = c / $$\lambda$$
h = 6.624E-32 Js

3. I have the f$$_{red}$$ = 4.62 x 10$$^{14}$$ s
and f$$_{blue}$$ = 6.67 x 10$$^{14}$$ s , it says their Powers are the same, so I go ahead and went and equaled:

P$$_{red}$$ to P$$_{blue}$$, which is:

P$$_{red}$$h$$_{red}$$f$$_{red}$$ = P$$_{blue}$$h$$_{blue}$$f$$_{blue}$$

but I am tired and can't see the relevance, because when I multiplied times h [in Js] and then I divide like explained, I get .6925, and the ANSWER is 1.44.