DP Physics (first assessment 2025)

Question EXE.2.HL.TZ0.2d

Date	Example questions Example questions	Marks available	[Maximum mark: 4]	Reference code	EXE.2.HL.TZ0.2d
Level	HL	Paper	2	Time zone	TZ0
Command term	Calculate	Question number	d	Adapted from	N/A

[Maximum mark: 4]

EXE.2.HL.TZ0.2d

Another explosion is produced at X. The sound from this explosion is detected twice at the geophone at Z. Some sound travels directly from X to Z through clay along path 2. Other sound travels through clay via Y along path 3.

The vertical thickness of the clay layer is d. The distance XZ is 80.0 m.

The time between the arrival of the sounds due to the path difference is 6.67 ms.

(d)

Calculate d.

[4]

Markscheme

distance difference $= (3000 \times 0.00667 =) 19.8$ m ✓

½ distance difference $= 9.9$ m so YZ $= 49.9$ m ✓

$d = (\sqrt{{YZ}^{2} - {(\frac{XZ}{2})}^{2}}) = \sqrt{49 . 9^{2} - 40^{2}}$ ✓