Because they are caused by your exercise
Answer:
7.39 m or 3.61 m
Explanation:
= Wavelength
f = Frequency = 90 Hz
v = Speed of sound = 340 m/s
Path difference of the two waves is given by

Velocity of wave


So, the location from the worker is 7.39 m or 3.61 m
C.) a magnetic field is the correct answer…
Mechanical energy
I think
Except when necessary for takeoff and landing, <span>the minimum safe altitude required for a pilot to operate an aircraft over other than congested area is an altitude of 1000 ft above the highest obstacle within a 2000 ft horizontal radius of the aircraft.
It is also good to know that apart from taking off and landing, the aircraft must not operate at a distance less than 500 ft from any person, vessel, structure or vehicle.</span>