35. Special Relativity
Inertial Reference Frames
35. Special Relativity Inertial Reference Frames
127PRACTICE PROBLEM
The utilization of lasers for caries removal and cavity preparation is based on the ablation technique, in which dental hard tissues are removed during laser irradiation. The laser beam (λ =2.94 μm ) emitted by an erbium-doped yttrium aluminum garnet (Er: YAG) laser is efficiently absorbed by the carbonated hydroxyapatite mineral of the tooth. For an Er: YAG laser, the power of a laser pulse with a pulse duration of 150 μs is about 200 mW. Calculate the number of photons hitting a tooth in each pulse.
The utilization of lasers for caries removal and cavity preparation is based on the ablation technique, in which dental hard tissues are removed during laser irradiation. The laser beam (λ =2.94 μm ) emitted by an erbium-doped yttrium aluminum garnet (Er: YAG) laser is efficiently absorbed by the carbonated hydroxyapatite mineral of the tooth. For an Er: YAG laser, the power of a laser pulse with a pulse duration of 150 μs is about 200 mW. Calculate the number of photons hitting a tooth in each pulse.