For a stationary siren on a firehouse is blaring at 81Hz. Assume the speed of sound to be 343m/s, the frequency perceived is mathematically given as'
F=81.721Hz
<h3>What is the frequency perceived by a firefighter racing toward the station at 11km/h?</h3>Generally, the equation for the doppler effect is mathematically given as
Therefore
F=81(343+3.05556)/343
F=81.721Hz
In conclusion, the frequency is
F=81.721Hz
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Answer:
Explanation:
In a uniform circular motion, since a complete revolution represents 2π radians, the angular velocity, which is defined as the angle rotated by a unit of time, is given by:
Here T is the period, that is, the time taken to complete onee revolution:
Replacing (2) in (1):
Answer:
a)30.14 rad/s2
b)43.5 rad/s
c)60633 J
d)42 kW
e)84 kW
Explanation:
If we treat the propeller is a slender rod, then its moments of inertia is
a. The angular acceleration is Torque divided by moments of inertia:
b. 5 revolution would be equals to rad, or 31.4 rad. Since the engine just got started
c. Work done during the first 5 revolution would be torque times angular displacement:
d. The time it takes to spin the first 5 revolutions is
The average power output is work per unit time
or 42 kW
e.The instantaneous power at the instant of 5 rev would be Torque times angular speed at that time:
or 84 kW