A Helium-Neon Laser Emits Light At $632.8 \mathrm {~nm}$ If the Laser Emits

Multiple Choice

A helium-neon laser emits light at $632.8 \mathrm {~nm}$ . If the laser emits $1.82 \times 1017$ photons/second, what is its power output in $\mathrm { mW } ? \left( c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$

A) $37.2 \mathrm {~mW}$
B) $57.2 \mathrm {~mW}$
C) $28.6 \mathrm {~mW}$
D) $45.7 \mathrm {~mW}$