Physics Stack: Center of Mass Equilibrium Puzzle
Challenge your spatial intuition and architectural equilibrium in Physics Stack! Position a motorized overhead crane, rotate diverse geometric polygons, and drop blocks onto an elevated narrow pedestal. Counterbalance rotational torque, absorb kinetic shockwaves, and construct towering multi-tiered spires. Hold your breath through the grueling 5-second stability countdown to prove absolute equilibrium in this hypnotic HTML5 physics builder.
Physics Stack
Stack all shapes on the narrow pedestal. Keep the tower balanced for 5 seconds to win each tier!
Physics Stack: Rigid Body Equilibrium & Center-of-Mass Strategy
Physics Stack reimagines structural engineering and classic block-stacking through authentic 2D rigid-body dynamics. Given a series of irregular geometric polygons—rectangles, squares, isosceles triangles, cylinders, and L-blocks—players must assemble a stable vertical spire atop a narrow, elevated platform. Every placement alters the system's combined center of gravity, introducing rotational torque, kinetic friction, and micro-vibrations.
How to Play: Step-by-Step Architectural Equilibrium
Position Crane Gantry
Move your mouse or slide your finger across the upper track to align the suspended shape directly over your planned drop coordinate.
Rotate Geometric Polygons
Tap Rotate (or press R/Up Arrow) to turn shapes 90 degrees. Turn triangles to form flat bases or orient rectangles horizontally for wide footprints.
Release the Block
Click Drop or hit Spacebar to let gravity take over. Minimize drop heights when possible to lessen initial impact shockwaves.
Survive the 5s Timer
Once all stage shapes are deployed, a 5-second balance timer initiates. If no pieces fall off the platform, victory is secured!
The Physics of Static Equilibrium and Rotational Torque
Achieving stability in Physics Stack requires obeying fundamental Newtonian laws:
- Base of Support: An object remains in stable equilibrium as long as its vertical gravity vector falls within its contact surface base. If the combined center of mass overhangs the support edge by even a single pixel, gravity induces a rotational moment (\(\tau = r \times F\)) that tips the structure.
- Damping & Kinetic Restitution: When dropping dense shapes from high elevations, impact energy creates elastic vibrations. Building an interlocking interlocking foundation with wider lower blocks absorbs seismic shocks without dislodging upper layers.
- Triangular Wedging: Slanted triangle faces create inclined planes that turn vertical weight into lateral sliding forces. Placing a cylinder or square on a slope requires counterbalancing friction or wedging between twin pillars.
Three Calibrated Difficulty Levels
- Easy Mode (Apprentice): 160px wide foundation platform, 3 retry lives, full vertical center-of-mass guide line, and predictable rectangular shapes.
- Medium Mode (Architect): 110px platform width, 2 retry lives, short alignment guide, and introduces rolling cylinders and steep ramps.
- Hard Mode (Master Structuralist): 70px razor pedestal, 1 single life, zero alignment guide, and challenging asymmetric multi-angle polygons.