Answer:

Explanation:
Use Doppler effect equation:
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. The general equation is given by:

- When the observer moves towards the source
is positive.
- When the observer moves away from the source
is negative.
- When the source moves towards the observer
is negative.
- When the source moves away from the observer
is positive.
Since the problem don't give us aditional information let's assume:

Which is the speed of sound in air.
And using the information provided by the problem:


The frequency perceived by the person is 331.046Hz
<em><u>Translation:</u></em>
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Usa la ecuación del Efecto Doppler:
El efecto Doppler es un fenómeno físico en el que una fuente de sonido presenta un cambio aparente en la frecuencia de onda con respecto a su observador cuando esa misma fuente está en movimiento. La ecuación general viene dada por:

- Cuando el observador se mueve hacia la fuente
es positivo.
- Cuando el observador se aleja de la fuente es
negativo.
- Cuando la fuente se mueve hacia el observador
es negativa.
- Cuando la fuente se aleja del observador
es positiva.
Como el problema no nos da información adicional, supongamos que:

La cuál es la velocidad del sonido en el aire.
Y utilizando la información proporcionada por el problema:

La frecuencia percibida por la persona es 331.046Hz
The one that's completely submerged is displacing more water, so the buoyant force on it is greater.
C. hydrogen accreted onto a white dwarf from a close companion rapidly fuses to helium, releasing a large amount of energy.
The accreted material, composed mainly of hydrogen, is compacted on the surface of the white dwarf due to the intense gravitational force on that place. As material accumulates, The white dwarf becomes increasingly hot, until it reaches the critical temperature for ignition of nuclear fusion.
Answer:
98 joules
Explanation:
1/2 of 28 = 14
14 multiply by 7= 98 joules
Answer:
c. 
Explanation:
= Initial distance between asteroid and rock = 7514 km = 7514000 m
= Final distance between asteroid and rock = 2823 km = 2823000 m
= Initial speed of rock = 136 ms⁻¹
= Final speed of rock = 392 ms⁻¹
= mass of the rock
= mass of the asteroid
Using conservation of energy
Initial Kinetic energy of rock + Initial gravitational potential energy = Final Kinetic energy of rock + Final gravitational potential energy
