To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is a physical phenomenon where an apparent change in wave frequency is presented by a sound source with respect to its observer when that same source is in motion. Mathematically it can be described as

The meaning of each of these variables is,
Velocity of detector
=Frequency of wave emitted by source
Velocity of source
v=Velocity of sound wave
=Frequency received by detector
Replacing we have that,


Therefore the correct option is e. 950Hz
Atmosphere, geosphere, cryosphere would be the correct answer I think
Answer:
1.- para cubrir la superficie lateral 4.32 metros²
2.- Area de la base 2.15 metros²
3.- Volumen 1 m³
4.- Area total 6.47 metros²
Explanation:
El área lateral sera calcular el area de seis triangulos iguales cuya base es
0.80 de base x 6 lados = 4.80 metros perimetro de la base
4.80 perimetro de base x 1.80 arista lateral / 2 = 4.32m2
Area de la base:
Perímetro x Apotema / 2
Siendo la Apotema la altura de los triangulos que componen un hexagono calculada utilizando el teorema de pitágoras:

Apotema = 0.894427191
Area: 4.80 x 0.894427191 / 2 = 2.146625258
sumando el area de la base mas el area lateral se obtiene el area total
2.15 + 4.32 = 6.47 metros
Volumen de la pirámide:
Area de la Base x Altura / 3
2.15 x 1.40 / 3 = 1.00333 m3