a sonic depth gauge is placed 4.3 m above the ground.

Question

A sonic depth gauge is placed 4.3 m above the ground. An ultrasound pulse sent downward reflects off snow and reaches the device 0.024 seconds after it was emitted. The air temperature is −20°C.

(a)

How far (in m) is the surface of the snow from the device? (Round your answer to at least three significant figures.)

 m

(b)

How deep (in m) is the snow?

 m

Answer 1

a) Speed of sound @ -20 degree centigrade is 319 m/s.

Distance = (319m/s x.024 s)/ 2 = 3.828 m

b) snow depth = 4.3 m - 3.828m = 0.472 m