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devlian [24]
3 years ago
10

single goose sounds a loud warning when an intruder enters the farmyard. Some distance from the goose, you measure the sound lev

el of the warning to be 81.0 dB. 1) If a gaggle of 26 identical geese is present, and they are all approximately the same distance from you, what will the collective sound level be if they all sound off simultaneously
Physics
1 answer:
Goryan [66]3 years ago
4 0

Answer:

The sound level of the 26 geese is  Z_{26}= 96.15 dB

Explanation:

From the question we are told that

    The  sound level is Z_1 =  81.0 \ dB

     The number of geese is N = 26

Generally the intensity level of sound is mathematically represented as

        The intensity of sound level in dB  for one  goose is mathematically represented as

                       Z_1 = 10 log [\frac{I}{I_O} ]

Where I_o is the  threshold level of intensity with value  I_o = 1*10^{-12} \  W/m^2

            I is the intensity for one goose in W/m^2

For 26 geese the intensity would be  

          I_{26} = 26 * I

   Then  the intensity of 26 geese in dB is  

              Z_{26} = 10 log[\frac{26 I }{I_o} ]

               Z_{26} = 10 log (\ \ 26 *  [\frac{ I }{I_o} ]\ \ )

               Z_{26} = 10 log (\ \ 26  \ \ ) *   (\ \  10 log [\frac{ I }{I_o} ]\ \ )

 From the law of logarithm we have that

              Z_{26} = 10 log 26 +  10 log [\frac{I}{I_0} ]

                    = 14.15 + 82

                    Z_{26}= 96.15 dB

               

               

           

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Answer:

Explanation:

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Work needed to burn this much of Cals = 1000 x 100 / 25 = 4000 Cals.

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Work done in one jump = kinetic energy while jumping

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2 years ago
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Answer:

the angular velocity of the rod immediately after being struck by the pellet, provided that the pellet gets lodged in the rod is = 0.5036 k` rad/s

Explanation:

Using the conservation of momentum of approach.

From the question; the pellet is hitting at a distance of 0.4 m down from the point of rotation of the rod.

So, the angular momentum of the system just before the collision occurs  with respect to the axis of the rotation is expressed by the formula:

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The position vector can now be :

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Also, given that :

v_{p,i}  ^ { ^  \to } = (280 \ i - 350 \  j)  \ m/s

Replacing the value into above equation (1); we have:

L_i ^ { ^  \to } =0.012 ((- \ 0.4 \  j) *(280 \ i - 350 \ j ))

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Also, the moment of inertia of the pellet about the axis of rotation is:

I_{pellet} = m_pr_y^2 \\ \\ I_{pellet} = 0.012 *0.4^2  \\ \\ I_{pellet} = 1.92*10^{-3} kg . m^2

So, the moment of inertia of the rod +pellet system is:

I = I_{rod}+I_{pellet}

I =( \frac{8}{3}+1.92 *10^{-3} )kg. m^2

I = 2.6686 \  kg. m^2

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L_f ^ {^ \to}  = I \omega { ^ {^ \to} } = 2.6686 \  \omega  ^ {^ \to}

The angular velocity of the rod \omega is determined by equating the angular momentum just before the collision with the final angular momentum (i.e after the collision).

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L_f ^ {^ \to} = L_i ^ { ^ \to}

2.6686 \omega ^ {^ \to} = 1.344 \ k ^ {^ \to}

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7 0
3 years ago
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Answer:

6.1 km

Explanation:

Given that a plane travels 4.0 km at an angle of 25◦ to the ground, then changes direction and travels 10 km at an angle of 16◦ to the ground. What is the magnitude of the plane's total displacement? Answer in units of km

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Answer:

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