Dual Nature of Matter and Radiation

Step 1: Understanding Power
Power is how much energy is used or given out each second. So: Power =‌

‌ Energy ‌

‌ Time ‌

Step 2: Energy of One Photon
The energy in one photon of light is found using: E=hf where h is Planck's constant and f is the frequency.
Step 3: Total Energy from Many Photons
If N photons come out in time t, the total energy is N×hf.
Step 4: Linking Power and Number of Photons
So, Power =‌

‌ Total Energy ‌

‌ Time ‌

=‌

N×hf

t

Step 5: Average Number of Photons per Second
The number of photons per second is n=‌

N

t

=‌

P

hf

Plug in the numbers: n=‌

33×10−3

6.6×10−34×5×1014

Step 6: Final Calculation
This works out to: n=10×1016 So, the laser gives off 10×1016 photons every second.