https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=82.19.218.32explain xkcd - User contributions [en]2026-05-14T22:03:16ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:3244:_Pullback_Drive&diff=412359Talk:3244: Pullback Drive2026-05-12T10:22:45Z<p>82.19.218.32: energy storage</p>
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Is that supposed to be Elon Musk?<br />
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There are toy cars that work like this, or that use a flywheel to store energy in a similar way, for example the Fisher-Price Rev 'N Go Stunt Vehicles. The salesman is offering a full sized car on the same principle.<br />
The toys don't go very far. Neither will the full sized car, though he implies it will go "far" before stopping. He doesn't offer any practical way to rewind the spring. [[Special:Contributions/2A12:F43:1462:CC00:583C:B3A7:2A0B:2140|2A12:F43:1462:CC00:583C:B3A7:2A0B:2140]] 09:56, 12 May 2026 (UTC) dww<br />
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Energy storage. The devil is in the detail, and the magnitudes. It turns out a rubber spring (aeroplane elastic) stores rather more energy weight for weight than a steel 'clockwork' spring. However batteries, and hydrocarbons, store orders of magnitude more. This subjectwould be good for one of Randall's 2D graphs, plotting use case against energy stored. For instance, a diver's harpoon gun uses a pull-back mechanism quite effectively.</div>82.19.218.32