Answer:
frequency = 1475.45 Hz
Explanation:
given data
frequency f1 = 1215 Hz,
frequency f2 = 1265 Hz
police car moving vp = 25.0 m/s
solution
speed of sound u = 343 m / s
speed of the other car = v
when the police car is stationary
the frequency the other car receives is
f2 = f1 ×
................1
and
the frequency the police car receives is
f2 = f1 ×
..................2
now from equation 1 and 2


v = 4.77 m/s
and
frequency the other car receives is
f2 = f1 ×
......................3
and
the frequency the police car receives is
f2 = f1 ×
.......................4
now we get
f2 = f1 ×
f2 =
f2 = 1475.45 Hz
Answer:
107 m
Explanation:
Convert km/h to m/s:
128.4 km/h × (1000 m / km) × (1 h / 3600 s) = 35.67 m/s
Distance = rate × time
d = 35.67 m/s × 3.0 s
d = 107 m
Answer:
therefore critical angle c= 69.79°
Explanation:
Canola oil is less dense than water, so it floats over water.
Given 
which is higher than that of water
refractive index of water 
to calculate critical angle of light going from the oil into water
we know that

now putting values we get

c= 
c=69.79°
therefore critical angle c= 69.79°
Answer:
7.08 m/s²
Explanation:
Given:
v₀ = 20.0 m/s
v = 105 m/s
t = 12.0 s
Find: a
v = at + v₀
105 m/s = a (12.0 s) + 20.0 m/s
a = 7.08 m/s²
<span>C.
Sample C would be best, because the percentage of the energy
in an
incident wave that remains in a reflected wave from this material
is the
smallest.
The coefficient of absorption is the percentage of incident sound
that's absorbed. So the highest coefficient of absorption results in
the smallest </span><span>percentage of the energy in an
incident wave that remains.
That's what you want. </span>