OneTaskBy Tim King · Updated
Catapult Game
Set the Angle and Power and Knock Down the Tower
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How the Catapult Game works
This catapult game is a physics puzzle about angle and power. A block tower stands somewhere to the right; a rock sits on the launcher at the left. Set the launch angle and power, use the dotted line to see where the rock will go, and press Fire. Every rock stays where it lands, so you can pile them up or use one to nudge a block that is already teetering. New tower builds a fresh one at a random distance; the storeys slider sets how tall it is.
Catapult game: how it works
This is the classic angle-and-power game — the same idea as Angry Birds, or the artillery games that go back to the 1970s — but the rock and the blocks obey a real 2D physics engine, so a hit on the tower's leg brings it down differently from a hit on the roof.
Reading the arc. The dotted preview is the ideal parabola for the angle and power you have chosen: horizontal speed stays constant while gravity accelerates the rock downward. It ignores air resistance, which in the simulation is negligible for a dense rock, so the preview matches the real flight closely up to the first collision. Maximum range is at 45 degrees; a lower angle gets there faster and flatter, a higher one drops in from above, which is often better for toppling the top storey onto the ones below.
Knocking blocks down. A block counts as down when it has fallen below the top of the tower or tipped past about 25 degrees. The tower is built from pairs of pillars with a slab across each pair, so the weak point is the pillars: hit one and the slab above pivots and takes the storey with it. Taller towers wobble more and are easier to start collapsing but need more storeys cleared.
Power sets the launch speed, scaled to the width of the stage so the same setting reaches the tower on any screen, and the rock is dense so it carries momentum through several blocks. Watch the shots counter and try to clear a tower in one; the best players find the angle that makes the rock land on the middle slab.
Everything is in the browser. The blocks, the rock and the launcher are rigid bodies in the Matter.js physics engine, and nothing is scripted — the same shot can end differently if a rock from an earlier shot is lying in the way. Pause, Save PNG and Reset work as in the other physics toys.
FAQ
Why does the rock not follow the dotted line?
It does until the first collision; after that the physics takes over. If it diverges earlier, a previous rock is lying in the path, since rocks stay where they land.
What angle gives the longest shot?
45 degrees. Lower angles arrive faster and flatter, which is good for hitting a pillar; higher angles drop in from above and are better for toppling the top storey.
How does the block count work?
A block is down once it falls below the top of the tower or tips past about 25 degrees. A slab that slides off but stays level is not counted until it falls.
Why is the tower a different distance each time?
New tower places it at random so the same angle and power do not work twice. The storeys slider sets height only. Watch where the last shot landed and adjust from there.
See also: all Simulations & Screensavers tools, Images, Audio, Video & Screen, PDF, SVG, Generative Art, Chart Makers, 3D Model Viewers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science, Tracker Music.
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