An ultrasound probe receives echoes from the front and back surfaces of an organ. The echoes arrive 30 μs30\ \mu\mathrm{s}30 μs apart. Ultrasound travels through the organ at 1600 m/s.
What is the thickness of the organ along the ultrasound path?
48 mm48\ \mathrm{mm}48 mm
12 mm12\ \mathrm{mm}12 mm
96 mm96\ \mathrm{mm}96 mm
24 mm24\ \mathrm{mm}24 mm