To develop this problem we will apply the concepts related to the Doppler effect. The frequency of sound perceive by observer changes from source emitting the sound. The frequency received by observer 
is more than the frequency emitted by the source. The expression to find the frequency received by the person is,
= Frequency of the source
= Speed of sound
= Speed of source
The velocity of the ambulance is
Replacing at the expression to frequency of observer we have,
Therefore the frequency receive by observer is 878Hz
Answer:
8 seconds
Explanation:
From Newton's second law;
Ft = m(v-u)
F = Force applied
t = time taken
v = final velocity
u = initial velocity
20 * t = 32 (9 - 4)
20t = 32 * 5
t = 32 * 5/ 20
t = 8 seconds
The cheetah's speed is 100x and
The gazelle's speed is 80x + 70.
Set the two equations equal to each other:
100x = 80x +70 (then subtract 80x from both sides).
20x = 70 (then divide by 20).
X =3.5.
The cheetah catches the gazelle after 3.5
Answer: anlien, enemy gnome, spaceship
Explanation:
the polluted urban environment affects the health and quality of life
