D is the best answer. In many physics problems we treat an extended object as if it were a point with the same mass located at the center of mass.
        
             
        
        
        
Answer:
  v ’= 21.44 m / s
Explanation:
This is a doppler effect exercise that changes the frequency of the sound due to the relative movement of the source and the observer, the expression that describes the phenomenon for body approaching s
            f ’= f (v + v₀) / (v- )
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where it goes is the speed of sound 343 m / s, v_{s} the speed of the source v or the speed of the observer
in this exercise both the source and the observer are moving, we will assume that both have the same speed,
                 v₀ = v_{s} = v ’
we substitute
                f ’= f (v + v’) / (v - v ’)
                f ’/ f (v-v’) = v + v ’
                v (f ’/ f -1) = v’ (1 + f ’/ f)
                v ’= (f’ / f-1) / (1 + f ’/ f) v
                v ’= (f’-f) / (f + f’) v
let's calculate
                 v ’= (3400 -3000) / (3000 +3400) 343
                 v ’= 400/6400 343
                 v ’= 21.44 m / s
 
        
             
        
        
        
Inertia is the resistance of an object to moving or stopping
        
                    
             
        
        
        
Answer:
10 litres.
Explanation:
The air fuel ratio for aircraft is 12:1. It is due to simplicity piper archer is equipped with continuous flow injection system. There is a fuel sensing is Piper Archer which informs the pilot about the low fuel when the fuel level reaches to as low as 10 litres only in the tank. The yellow low furl light will illuminate to alert the pilot.
 
        
             
        
        
        
I think its a higher frequency