Introduction to Robotics/Printouts/Sound Waves

Name:_________________________________

Date: 09 / 30 / 2026
Sound Waves

Speed of sound

<math>D = Ct</math>

D is the distance, measured in meters.

C is the speed of sound in air, measured in meters per second.

t is the amount of time the wave travels, measured in seconds.

Convert to Centimeters

We convert to centimeters because they are more useful, and it helps to remove fractions from our calculation.

<math>D = Ct \times \frac{100cm}{1m} = 100Ct</math>

For the BoeBot

<math>D = \frac{100CT}{2}</math>

Because the sound wave must travel to the object and back.

The BoeBot measures t in "clock cycles", which are each 2μseconds. We must convert the equation to use seconds instead of clock cycles:

<math>D = \frac{100Ct}{2}\times\frac{2}{1,000,000} = frac{Ct}{10,000} = 0.03448t</math>

At 72°, sound travels at 344.8m/s.

Fractional Math

The BoeBot can do some limited math with fractions.

The "**" operator is used as follows:

<math>A**B = A \times \frac{B}{65536}</math>

We calculate that:

We can use the following code to convert time to distance:

Distance = Conversion ** time

Finding the Conversion Constant

<math>Conversion = 0.03448 \times 65536 = 2260</math>