An industrial ultrasound probe is used to detect an internal void inside a structural polymer composite component as shown in the oscilloscope trace below.
a.[1]
Which of the following is the same as 3.2 microseconds (μs)3.2\text{ microseconds } (\mu\text{s})3.2 microseconds (μs)?
- 3.2×10−3 s3.2 \times 10^{-3}\text{ s}3.2×10−3 s
- 3.2×10−6 s3.2 \times 10^{-6}\text{ s}3.2×10−6 s
- 3.2×10−9 s3.2 \times 10^{-9}\text{ s}3.2×10−9 s
- 3.2×10−12 s3.2 \times 10^{-12}\text{ s}3.2×10−12 s
b.[4]
Ultrasound travels at 2500 m/s2500\text{ m/s}2500 m/s in this polymer composite.
Determine the depth of the void below the top surface of the component.
Give your answer to two significant figures.