Question

During an ultrasound, sound waves are sent by a transducer through muscle tissue at a speed of 1300 m/s. Some of the sound waves are reflected from a metal fragment 3.0 cm into the muscle tissue. How long did it take the transducer to detect the reflected waves from the metal fragment after they were first emitted?
23 seconds
39 seconds
2.3 x 10−5 seconds
3.9 x 10−5 seconds

Answer 1

$2.3 \times 10^{-5} \text { seconds }$ is the time taken by the transducer to detect the reflected waves from the metal fragment after they were first emitted

Option C

Explanation:

Given data:

speed, v = 1300 m/s

distance, d = 3.0 cm = $3.00 \times 10^{-2} \mathrm{m}$

We need to calculate the time taken by the transducer to detect the reflected waves from the metal fragment after they were first emitted.

As we know, the velocity is the ratio of distance and the time travelled by an object. The equation form is given by,

              $\text {velocity, } v=\frac{\text {distance }(d)}{\text {time}(t)}$

By applying the given values to the above equation, we get

              $1300=\frac{3.00 \times 10^{-2}}{t}$

              $t=\frac{3.00 \times 10^{-2}}{1300}=0.002307 \times 10^{-2}=2.3 \times 10^{-5} \text { seconds }$