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SVETLANKA909090 [29]
3 years ago
13

17. A microphone of surface area 2.0 cm’ absorbs 1.1 mW of sound. What is the intensity

Physics
1 answer:
Oxana [17]3 years ago
3 0

Answer:

I=0.055\ W/m^2

Explanation:

Given that,

A microphone of surface area 2.0 cm’ absorbs 1.1 mW of sound.

Surfrace area, A = 2 cm = 0.02 m

Power absorbed, P = 1.1 mW = 0.0011 W

We need to find the intensity of sound hitting the microphone. Power per unit area is called the intensity of sound. It can be given by :

I=\dfrac{P}{A}\\\\=\dfrac{0.0011\ W}{0.02\ m^2}\\\\=0.055\ W/m^2

So, the intensity of sound is 0.055\ W/m^2. Hence, the correct option is (b).

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510 g squirrel with a surface area of 935 cm2 falls from a 4.8-m tree to the ground. Estimate its terminal velocity. (Use the dr
Yuki888 [10]

Answer:

The terminal velocity is v_t  =17.5 \ m/s

Explanation:

From the question we are told that

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      The surface area is   A_s =  935 cm^2  =  \frac{935}{10000} = 0.0935 \ m^2

       The height of fall is  h =4.8 m

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          The width of the prism is w =  11.6 =  0.116 \ m

 

The terminal velocity is mathematically represented as

       v_t  =  \sqrt{\frac{2 * m_s *  g }{\dho_s * C  * A } }

Where \rho  is the density of a rectangular prism with a constant values of \rho  =  1.21 \ kg/m^3

            C is the drag coefficient for a horizontal skydiver with a value = 1

            A  is the area of the prism the squirrel is assumed to be which is mathematically represented as

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