DP Physics (last assessment 2024)
Question 18M.3.HL.TZ2.b.ii
| Date | May 2018 | Marks available | [Maximum mark: 3] | Reference code | 18M.3.HL.TZ2.b.ii |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Calculate | Question number | b.ii | Adapted from | N/A |
b.ii.
[Maximum mark: 3]
18M.3.HL.TZ2.b.ii
The attenuation values for fat and muscle at different X-ray energies are shown.
A monochromatic X-ray beam of energy 20 keV and intensity I0 penetrates 5.00 cm of fat and then 4.00 cm of muscle.
Calculate, in terms of I0, the final beam intensity that emerges from the muscle.
[3]
Markscheme
after fat layer, Ifat = I0e–0.4499 × 5.00
after muscle layer, I = Ifate–0.8490 × 4.00
I = 0.003533 I0 or 0.35%
[3 marks]
