{"id":58424,"date":"2026-01-06T04:50:49","date_gmt":"2026-01-05T19:50:49","guid":{"rendered":"https:\/\/phys-edu.net\/wp\/?p=58424"},"modified":"2026-01-06T04:50:49","modified_gmt":"2026-01-05T19:50:49","slug":"reveal-the-invisible-force-exploring-action-and-reaction-with-a-force-sensor","status":"publish","type":"post","link":"https:\/\/phys-edu.net\/wp\/?p=58424&lang=en","title":{"rendered":"Reveal the Invisible Force! Exploring Action and Reaction with a Force Sensor"},"content":{"rendered":"

Hi, I’m Ken Kuwako, your Science Trainer. To me, every day is a new experiment!<\/strong><\/span><\/p>\n

“If only we could actually see force…” Have you ever felt that way while sitting in a science class\u2014or perhaps while teaching one? In the world of physics, “force” is the foundation of everything. However, because it is invisible, trying to imagine it solely in your head is a monumental task. For many middle school students, mechanics becomes the first major wall they hit in their studies.<\/p>\n

Digital sensor technology is the tool that vividly brings this “invisible world” to light. While people often shy away from these devices thinking they are too expensive or difficult to set up, having just one for demonstrations can dramatically increase how much a lesson resonates with students. Today, I want to introduce an experiment using my favorite tools\u2014Narika\u2019s “EasySense” and “Force Sensors”\u2014to visualize a vital principle of physics: Newton’s Third Law, also known as the Law of Action and Reaction.<\/p>\n

Visualizing Invisible Force: The Magic of the Force Sensor<\/strong><\/h3>\n

A major turning point in understanding physics is whether or not a person can perceive force as a “vector” (something with both direction and magnitude). This is exactly where the Force Sensor<\/strong> comes to the rescue.<\/p>\n

The most iconic example of a force you can “see” through data is the Law of Action and Reaction<\/strong>. You know the one: “If you punch a wall, the wall punches you back with the same amount of force.” Even if we understand the logic, it is difficult to capture the exact moment two identical forces act in opposite directions. In this experiment, we use two sensors and set them up so that one moves in a positive direction while the other moves in a negative direction on the graph. This allows us to visualize the movement of force as if it were reflecting in a mirror.<\/p>\n

Science Recipe: Witnessing Action and Reaction<\/strong><\/h3>\n

What You Need<\/h3>\n

EasySense, 2 Force Sensors, Windows PC, Ultrasonic Sensor, 2 Dynamics Carts, and weights.<\/p>\n

\"\"<\/p>\n

This is the Force Sensor.<\/p>\n

The Method<\/h3>\n

Attach a force sensor to each of the two dynamics carts.<\/p>\n

Face the carts toward each other and let them collide.<\/p>\n

\"\"<\/p>\n

Add a weight to one of the carts (changing its mass) and try the collision again.<\/p>\n

Experiment Results: The Mirror World Appears in Real-Time<\/strong><\/h3>\n

When you perform the experiment, the changes in force are recorded on the computer screen in real-time. First, let\u2019s look at what happens when we gently press the two force sensors against each other.<\/p>\n