Problem: a) What is the intensity in W/m² of a laser beam used to burn away cancerous tissue that, when 89.5% absorbed, puts 497 J of energy into a circular spot 2.01 mm in diameter in 4.00 s? b) How many times more intense is this than the maximum intensity of direct sunlight (about 1360 W/m²)?

FREE Expert Solution

Intensity of the beam:

I=EAt=Eπr2t

a)

r = 2.01/2 = 1.005 mm

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Problem Details

a) What is the intensity in W/m² of a laser beam used to burn away cancerous tissue that, when 89.5% absorbed, puts 497 J of energy into a circular spot 2.01 mm in diameter in 4.00 s? 

b) How many times more intense is this than the maximum intensity of direct sunlight (about 1360 W/m²)?

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