Electromagnetic radiation from a 5.00-mW laser is concentrated on a 1.00-mm2 area. What is the intensity in W/m2?

Explanation:

Given

Electromagnetic radiation = 5.00mW

Convert to watts

5.00mW=5×10^-3 watts

Area = 1.00mm² = 1.00mm×1.00mm

Converting to m²

1.00mm² = 1×10^-3m × 1×10^-3m

1.00mm² = 1×10^-6m²

Intensity = 5×10^-3 watts/ 1×10^-6m²

Intensity = 5 × 10^-3-(-6)W/m²

Intensity = 5×10^(-3+6)W/m²

Intensity = 5×10³W/m²

the part of the wave he is travelling on is the crest