Please help me with the calculation from Physics

[DEWANA]

Hi guys I hope U can help me with this calculation...

Im very bad in Physics...I have no Idea how to caluculate this equation
And I don't no how to start...please helppp mee...It help me very much to see how you calculate it THANK YOU VERY MUCH:

It says:
Use the data from the table below to calculate the specific acousstic impedance, Z of
i) air, ii) skin, iii) fat. Use the equation Z = pc

Medium Densit (p) kg m-3 Ultrasound velocity (c) m s-1
air 1.3 330
skin 1060 1540
fat 925 1450


Using the following equation:

α = (Z2 - Z1)
(Z2 + Z1)

caluculate the intensity reflection coefficient, α at iv) an air-skin boundary, v) a skin-fat boundary. Show all stages of your working.

 

[DEWANA]

Please help me in Physics caluculation

Hi guys I hope U can help me with this calculation...

Im very bad in Physics...I have no Idea how to caluculate this equation
And I don't no how to start...please helppp mee...It help me very much to see how you calculate it THANK YOU VERY MUCH:

It says:
Use the data from the table below to calculate the specific acousstic impedance, Z of
i) air, ii) skin, iii) fat. Use the equation Z = pc

Medium
air
skin
fat

Density (p) kg m -3
1.3
1060
925

Ultrasound velocity (c) m s-1
330
1540
1450




Using the following equation:

α = (Z2 - Z1)
(Z2 + Z1)




caluculate the intensity reflection coefficient, α at iv) an air-skin boundary, v) a skin-fat boundary. Show all stages of your working.

Thank U so much

 

[arildno]

It says:
Use the data from the table below to calculate the specific acousstic impedance, Z of
i) air, ii) skin, iii) fat. Use the equation Z = pc

Medium Densit (p) kg m-3 Ultrasound velocity (c) m s-1
air 1.3 330
skin 1060 1540
fat 925 1450


Are you seriously saying you are unable to calculate Z=pc in these three cases?

 

[DEWANA]

Hi arildno thanks for the quick answer...but serious I have no Idea how to caluculate it! If You know please helpp me...

thanks

maria )

 

[arildno]

What does "Z" stand for?
What does "p" stand for?
What does "c" stand for?

Answer those questions.

 

[dynamicsolo]

Use the data from the table below to calculate the specific acousstic impedance, Z of
i) air, ii) skin, iii) fat. Use the equation Z = pc

Is this issue here that you don't understand what is meant by 'pc'? For this part, they are just asking you to multiply together the values given in the table for each substance.

Using the following equation:

? = (Z2 - Z1)
(Z2 + Z1)

caluculate the intensity reflection coefficient, ? at iv) an air-skin boundary, v) a skin-fat boundary. Show all stages of your working.

For this second part, you would use the appropriate values of Z that you found in the first part to calculate $$\alpha$$ for each possible pair of substances. (Arrange the values in the numerator so that the difference is always positive.)

You are welcome to show the results you found if you have any questions about whether they are correct...

 

[TVP45]

Hi guys I hope U can help me with this calculation...

Im very bad in Physics...I have no Idea how to caluculate this equation
And I don't no how to start...please helppp mee...It help me very much to see how you calculate it THANK YOU VERY MUCH:

It says:
Use the data from the table below to calculate the specific acousstic impedance, Z of
i) air, ii) skin, iii) fat. Use the equation Z = pc

Medium Densit (p) kg m-3 Ultrasound velocity (c) m s-1
air 1.3 330
skin 1060 1540
fat 925 1450


Using the following equation:

α = (Z2 - Z1)
(Z2 + Z1)

caluculate the intensity reflection coefficient, α at iv) an air-skin boundary, v) a skin-fat boundary. Show all stages of your working.

DEWANA,
I ask this in what I hope you take as helpful. Do you know the physical meaning of what you are calculating? This reflection coefficient tells you what happens when a sound wave traveling in one medium (like water) hits the boundary between that medium and another medium (say air, or rock, or steel). If you have further interest, you might look up how sonar works and how the waves are reflected from the boundary between seawater and a steel hull. It tells you how a sonar operator knows the difference between a whale and a Red October or why hulls are sometimes coated with a substance similar to rubber. Sonar is not nearly the only application, but it might be interesting to see what the calculation means.