Question

The intensity of an x-ray is to lose 40% of its original value when penetrating only 2 cm inside an object. What would be the percentage of the lost intensity when penetrating further 4 cm?

Answer 1

I think this can be solved with just math. So to go through 2cm, it loses 40%. So go through another 2cm, it will lose another 40% of what was already lost. Can you calculate that?

Answer 2

To*

Answer 3

Let me rephrase that: To go through another 2 cm, it will lose another 40% of what is left after losing the first portion.

Answer 4

@Thane
If you are looking for a physical interpretation of @wolfe8 solution, consider the fact that both Energy and Intensity are a function of square of Amplitude (of wave).

So energy dissipation can be considered in terms of loss of intensity.