Sci-Supply Inertia Demonstrator – Newton’s First Law of Motion Physics Classroom Apparatus

Bring Newton’s First Law to Life

Demonstrate Newton’s first law of motion in a clear, hands-on way with this durable inertia demonstrator from Sci-Supply. This classic device shows that objects tend to “keep on doing what they’re doing” unless acted upon by an unbalanced force. It’s a simple, reliable tool that helps students see inertia in action instead of just reading about it.

When you pull back the metal post (spring) and release it, it strikes the plastic plate under the red ball that sits above the blue receiver. Most students expect the ball to move sideways with the plate—but instead, it drops straight down into the receiver, demonstrating that an object at rest will remain at rest unless acted on by an external force.

How It Works

• The red ball rests on a plastic plate covering the blue receiver

• A metal post (spring) is pulled back and released

• The spring strikes the plate quickly, knocking it out from under the ball

• The plate moves out of the way, but the ball’s inertia keeps it at rest

• The ball drops directly into the blue receiver, clearly illustrating Newton’s first law

This quick, dramatic demonstration helps students connect everyday language like “objects resist changes in motion” with what they actually see in front of them.

Classroom-Friendly Design & Uses

• Simple setup and operation—no power required

• Ideal for middle school, high school, and introductory college physics

• Perfect for lessons on inertia, forces, and Newton’s laws of motion

• Great as a demo at the front of the room or as a station lab

• Rugged enough for repeated classroom use

Use the inertia demonstrator to spark discussion, make predictions, and challenge misconceptions about motion and forces. It’s a staple mechanics demo that fits easily into any physics or physical science unit.

Pairs well with our Magnetic Lines of Force Demonstrator for a complete forces and fields lesson.