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>
<em><u></u></em>
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 given problem can be exemplified in the following diagram:
Since there is no friction or any other external force, the only force acting in the direction of the movement is the component of the weight of the block, therefore, applying Newton's second law:

Replacing the values:

We may cancel out the mass:

Using the gravity constant as 9.8 meters per square second:

Solving the operations:

Therefore, the acceleration is 6.3 meters per square second.
Answer:
Option B, Some of the cars' kinetic energy was converted to sound and heat energy.
Explanation:
In an elastic collision, no energy is lost during and after collision. Thus, it can be said that in an elastic collision both momentum and kinetic energy remains conserved.
While in non-elastic collision, kinetic energy of the system is lost. However, the momentum of the system is conserved. Generally, during and after collision some of the kinetic energy is lost as thermal energy, sound energy etc.
Hence, option B is correct
Explanation:
The five-step process for treating a muscle or joint injury such as an ankle sprain is called "P.R.I.C.E." which is short for Protection, Rest, Ice, Compression, and Elevation).