A slab of material of thickness 10 cm reduces the amount of

A slab of material of thickness 1.0 cm reduces the amount of radiation by a factor of 3.0. How much is the radiation reduced (from its original amount) if you use a 3.0 cm thickness of this material? (Answer by the factor by which it\'s reduced, so your answer should be > 1; e.g., if it\'s cut in 1/2, you would answer 2.)

Solution

For radiation on the slab

I(x) = (Io e^(-alpha*x))

so, 1/3 = e^(-alpha*1)

alpha = 1.09

I(x) = Io e^(-1.09*3)

I/Io = 1/26.31

so I us reduced by a factor of 26