# Homework Help: Waves - diffraction

1. Apr 28, 2010

### jsmith613

1. The problem statement, all variables and given/known data
Waves with small wavelengths diffract less than those with longer wavelengths. Use this information to suggest why ultrasound is much better than ordinary waves for finding the depth of the sea [3 marks]

2. Relevant equations
NONE

3. The attempt at a solution
Ultrasound has a smaller wavelength than normal waves - hence wave is more concentrated on sea bed.

4. Problems

The mark scheme includes the following two, extra, factors
- amplitude decreases rapidly
- range limited / cannot travel far.

I presume that the last to factors refer to ordinary waves

Is this next sentences correct:
"the amplitude (energy) of an ultrasound wave decreases less rapidly than that of a normal wave - hence results will be more accurate and more responsive. Furthermore, ultrasound can travel further in water than normal waves"

Last edited: Apr 29, 2010
2. Apr 29, 2010

### jsmith613

Is this stuff correct?