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enc08

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Hi,

Please refer to the attached image.

T1 and T2 are ultrasound transducers. The focal point of the transducers is 2cm into the liver tissue.

I seem to be getting the wrong answer. This is what I'm doing:

The arrival time from T2 is: [tex]t_{T2} = 1cm/1450 + 2cm/1540 = 19.9us[/tex]

From this we can calculate an equivalent average speed across both tissue:

[tex]c_{equiv} = 3cm/19.9us = 1508.8m/s[/tex]

Using this we'll calculate the arrival time for T1

[tex]t_{T1} = \sqrt{(9.6mm)^2 + (3cm)^2}/c_{equiv} = 20.9us[/tex]

Thus the difference in arrival time is [tex]1us[/tex]

However the answer sheet indicates [tex]0.4us[/tex]

Thanks for your input.

Please refer to the attached image.

T1 and T2 are ultrasound transducers. The focal point of the transducers is 2cm into the liver tissue.

Q) A pulse is emitted from both transducers at the same time. Calculate the difference in arrival time at the focal point.Q) A pulse is emitted from both transducers at the same time. Calculate the difference in arrival time at the focal point.

I seem to be getting the wrong answer. This is what I'm doing:

The arrival time from T2 is: [tex]t_{T2} = 1cm/1450 + 2cm/1540 = 19.9us[/tex]

From this we can calculate an equivalent average speed across both tissue:

[tex]c_{equiv} = 3cm/19.9us = 1508.8m/s[/tex]

Using this we'll calculate the arrival time for T1

[tex]t_{T1} = \sqrt{(9.6mm)^2 + (3cm)^2}/c_{equiv} = 20.9us[/tex]

Thus the difference in arrival time is [tex]1us[/tex]

However the answer sheet indicates [tex]0.4us[/tex]

Thanks for your input.