An ultrasound probe produces ultrasound with a frequency of 2.0 MHz.
The ultrasound passes from soft tissue into bone.
The Table shows the speed of ultrasound in each material.
Table
| Material | Speed of ultrasound in m/s\text{m/s}m/s |
|---|---|
| soft tissue | 1540 |
| bone | 4080 |
Calculate the wavelength of the ultrasound in the soft tissue.
Calculate the increase in the wavelength of the ultrasound when it passes from the soft tissue into the bone.
Explain why the frequency of the ultrasound does not change when it passes from the soft tissue into the bone.
A student says:
'The ultrasound could become audible sound in the bone because its wavelength gets longer.'
Explain why the student is wrong.