Question

A laser produces 15.0mW of light. In 3.00hr , the laser emits 4.53×1020 photons. What is the wavelength of the laser?

Answer 1

1 watt = 1 J/s
15 watt = 15 J/s
15 milliwatts = 15 millijoules/s =0.015 J/s
0.015 J/s x (60 s/min) x (60 m/hr) x (3 hrs) = ? total Joules This E is for 4.53E20 photons so total J/4.53E20 = energy in J/1 photon. Then
E in J/photon = hc/wavelength. Solve for wavelength.

Answer 2

I got 5.56*10^-45 which doesn't make sense?

Answer 3

If you will show your work perhaps I can find it as in the other laser problem.

Answer 4

I think the error is in the exponent.

Answer 5

.015*60*60*3= 1.62*10^2 so 1.62*10^2/4.53*10^20= 7.34*10^22 so 7.34*10^22= (6.626*10^-34)(3.00*10^8)/wavelength and I solved for wavelength and got 2.71*10^-4 this tim

Answer 6

I don't know what you're doing wrong with your calculator but you need to find out and get it under control.
162/4.53E20 = approx 40E-20 or 4E-19 (I think the actual number is 3.57E-19). (both numbers wrong). My final answer comes out to be about 5.6E-7 m which is about 560 nm.