Answer:
Initial velocity = 10 m/s
θ = 60°
This is the case of projectile motion
So the horizontal component of velocity 10 m/s = 10 cosθ
u = 10 cosθ
u = 10 cos 60°
u=5 m/s
x= 5 m
So in the horizontal direction
x = u .t
5 = 5 .t
t = 1 sec The vertical component of velocity 10 m/s = 10 sinθ
Vo= 10 sinθ
Vo= 10 sin 60°
Vo = 8.66 m/s
h=3.75 m
So height of robot = 3.75 - 0.75 m
height of robot =3 m
The perceived frequency when the fire truck is moving toward you and away from you will be 370 Hz and 329.59 Hz respectively.
<h3>What is the Doppler effect?</h3>
A sudden change in the frequency due to the distance between the objects and source is explained by the doppler effect.
As the source and observer travel toward each other, the frequency of sound, light, or other waves increases or decreases.
The perceived frequency when the fire truck is moving toward you;
The perceived frequency when the fire truck is moving away from you;
Hence, the perceived frequency when the fire truck in cases 1 and 2 will be 370 Hz and 329.59 Hz.
To learn more about the doppler effect refer to the link;
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