Feb 12, 2007
Newton’s Laws Explained With Lego
Everyone who studies any science at school will have come across Newton’s Laws of Motion. His three physical laws explain the relationships between the forces acting on a body and the motion of that body and were first published in 1687 in his magnum opus – Philosophiae Naturalis Principia Mathematica.
Newton’s laws underpin so-called classical mechanics, as opposed to quantum mechanics or relativity theory. I’ve summarised them below, but you’ll get a much clearer understanding of bodies in motion if you watch the video.
- Objects stay still or move with constant velocity unless a force pulls on them or gives them a shove
- Pulling or shoving an object changes its velocity (accelerates it) at a rate proportional to the force of the pull or shove
- If you shove or pull an object it will pull or shove back with an equal and opposite force
And remember, gravity isn’t just a good idea, it’s the law!


No, there just three laws ascribed to Newton:
First law: The velocity of a body remains constant unless the body is acted upon by an external force.
Second law: The acceleration a of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma.
Third law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear.
There are many laws of Newton