Answer:
b) 472HZ, 408HZ
Explanation:
To find the frequencies perceived when the bus approaches and the train departs, you use the Doppler's effect formula for both cases:

fo: frequency of the source = 440Hz
vs: speed of sound = 343m/s
vo: speed of the observer = 0m/s (at rest)
v: sped of the train
f: frequency perceived when the train leaves us.
f': frequency when the train is getTing closer.
Thus, by doing f and f' the subjects of the formulas and replacing the values of v, vo, vs and fo you obtain:

hence, the frequencies for before and after tha train has past are
b) 472HZ, 408HZ
Answer:
The answer to your question is: 13.2 m/s
Explanation:
final speed (fs) = 77 m/s
t = 6.5 s
gravity (g) = 9.81 m/s2
initial speed (is) = ?
Formula
fs = is + gt from this equation we clear "is" = fs - gt
Substitution is = 77 - (9,81)(6.5)
Process is = 77 - 63.8
is = 13.2 m/s
Answer:
ثر أنواع التربة خصوبة التربحمراء .
ج- السوداء
Explanation:
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Answer:
42m/s
6.06s
Explanation:
To find the initial velocity and time in which the ball is fling over the ground you use the following formulas:

θ: angle = 45°
vo: initial velocity
g: gravitational constant = 9.8m/s^2
x_max: max distance = 180 m
t_max: max time
by replacing the values of the parameters and do vo the subject of the first formula you obtain:

with this value of vo you calculate the max time:

hence, the initial velocity of the ball is 42m/s and the time in which the ball is in the air is 6.06s
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TRANSLATION:
Para encontrar la velocidad inicial y el tiempo en el que la pelota está volando sobre el suelo, use las siguientes fórmulas:
θ: ángulo = 45 °
vo: velocidad inicial
g: constante gravitacional = 9.8m / s ^ 2
x_max: distancia máxima = 180 m
t_max: tiempo máximo
reemplazando los valores de los parámetros y haciendo el tema de la primera fórmula que obtiene:
con este valor de vo usted calcula el tiempo máximo:
por lo tanto, la velocidad inicial de la pelota es de 42 m / sy el tiempo en que la pelota está en el aire es de 6.06 s
Light travels in waves AND in bundles called "photons".
It's hard to imagine something that's a wave and also a bundle.
But it turns out that light behaves like both waves and bundles.
If you design an experiment to detect waves, then it responds to light.
And if you design an experiment to detect 'bundles' or particles, then
that one also responds to light.