One of the most versatile ways for students to measure motion—a key scientific concept—is the
Go Direct^® Motion Detector.

This sensor uses ultrasound to measure the position, velocity, and acceleration of moving objects. Specifically, the Go Direct Motion Detector sends out an ultrasonic pulse, or a sound wave at a frequency beyond human hearing, and then it listens for the echo from its target. 

Based on the amount of time the sound wave takes to go out and come back, the motion detector calculates how far away the object is. It measures a position at each time interval, so you end up with a graph of position vs. time. 

Here are some activities in which you can have students engage with the Go Direct Motion Detector:  

• Throw a ball above it.
• Move themselves in front of it.
• Put it on a track and measure the motion of carts moving on the track.

To help you get the most out of this versatile sensor, I’ve put together a list of three helpful strategies and best practices to get good, clean data.

#1: Be Aware of the Environment Around You

The Go Direct Motion Detector features a gold foil transducer that looks like an eye but acts like an ear; essentially, it’s a highly sensitive microphone that listens for the pitch or frequency of the ultrasonic sound wave bouncing off the object in motion. 

#2: Be Aware of the Target

With the Go Direct Motion Detector, sound waves go out, reflect off an object in motion, and then come back to the sensor. It’s important to know that some objects are better reflectors than others.

In general, people (i.e., students in your physics class) are good reflectors. To set your students up for success, consider having them hold a textbook, small whiteboard, or similarly flat and solid object in front of them. You can tell them to think of the object as the target for the sensor’s ultrasonic pulse.

Round objects can also work well as a target for the Go Direct Motion Detector—as long as they are large enough. For instance, you can get a good reflection off a softball, but a golf ball would be too small.

#3: Use Alternate Channel Settings as Necessary

The Go Direct Motion Detector is a multi-channel sensor. The Motion channel is the default. Two other channels of note are the “Motion-Cart” channel and the “Motion-TC” or Temperature Compensation channel.

However, if you take the sensor into the field and use it on a particularly hot or cold day, turning on the Motion-TC channel allows the Go Direct Motion Detector to automatically compensate for the air temperature and improve the sensor’s accuracy.

Want to learn more tips and tricks for this versatile sensor? Check out Maximizing Motion: Getting to Know the Go Direct Motion Detector. In this webinar, I go over best practices for using this sensor in a variety of lab activities; ways you can use the motion detector all year long; and how to make the most of the Vernier Graphical Analysis^® Pro app with your motion detectors to analyze, annotate, and share your data.

We’re always happy to brainstorm ideas for how to use the Go Direct Motion Detector—and we love to hear how educators are using this sensor for hands-on physics learning! Contact us at physics@vernier.com or 888-837-6437.

Maximizing Motion: Getting to Know the Go Direct® Motion Detector