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GCSE Questions: Medical Physics

- scanning and therapy

Q7. X-rays and ultrasound can both be used for scanning internal organs.

(a) Ultrasound is used to scan unborn babies but X-rays are not used to scan unborn babies.

Explain why.

[3 marks]

(b) The behaviour of ultrasound waves when they meet a boundary between two different materials is used to produce an image.

Describe how.

[2 marks]

(c) The diagram below shows two pulses from a scan of an unborn baby.

The emitted pulse is labelled A.

The returning pulse picked up by the receiver is labelled B.

The closest distance between the unborn baby and the mother's skin is 4.0 cm.

Use information in the diagram above to calculate the average speed of the pulse.

[3 marks]

(Total 8 marks)