Question

A sonic depth gauge is placed 5.8 m above the ground. An ultrasound pulse sent downward reflects off snow and reaches the device 0.031 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.)


(b)
How deep (in m) is the snow?

Answer 1

The speed of air at −20°C is equal to 318.8 m/s

(a) Distance to snow is equal to

$$\frac {318.8 m/s \times 0.031 s} {2}=4.941 m$$

(b) How deep (in m) is the snow?

5.8 m-4.941 m=0.859 m

Answer:

(a) 4.941 m

(b) 0.859 m