Playground demo: physics in motion
The explico playground is a compact, working course about motion in the plane and projectile motion. It is both a readable introduction to the physics and a live demonstration of the features that explico validates and renders.
What is in the course
The playground contains four short lessons in two parts:
Motion in the plane
- Position and coordinate systems — locate a point in Cartesian and polar coordinates, convert between them, and read velocity and acceleration off position as time derivatives, closing on the constant-acceleration case.
- Constant acceleration — predict velocity from initial velocity, acceleration, and elapsed time.
Projectile motion
- Projectile range — derive and calculate the horizontal range of a projectile launched over level ground.
- Optimal launch angle — explain why 45° maximises range in the idealised model.
The course assumes level ground, constant gravitational acceleration, and no air resistance. Interactive plots let you change the launch conditions and see how the trajectory and range respond.
What it demonstrates
This is the engine's end-to-end example rather than a static screenshot. It includes hoverable notation cards, worked examples, citations, knowledge checks, numbered equations, cross-referenced figures and tables, derivation diagrams, a notation glossary, a curriculum map, and a reader-visible knowledge version.
Every page is built from the same content schemas and validation pipeline that a larger explico course uses. That makes the playground useful for seeing both the reading experience and the authoring conventions in a small, inspectable course.
