# Pull-back toy car's mechanism can replace electric city cars **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 25, 2024, 6:29pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349 "2024-03-25T18:29:02Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![ZonexandScout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zonexandscout/32/544_2.png) [@ZonexandScout](https://boards.straightdope.com/u/ZonexandScout)\ **Post date:** [March 27, 2024, 5:32pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/21 "2024-03-27T17:32:32Z")
True. Maybe a mechanical arm to hook the bumper on the other car. It would just be very efficient drafting. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [March 27, 2024, 5:36pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/22 "2024-03-27T17:36:42Z")
> [@markn\_1](#): > > When it moves forward, it will hit the line of cars in front of it and get them all moving. That’ll never work! Haven’t you seen a Newton’s Cradle in action? Only the first car in line will move! ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [March 27, 2024, 5:41pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/23 "2024-03-27T17:41:40Z")
> [@ZonexandScout](#): > > Maybe a mechanical arm to hook the bumper on the other car. I have an old single panel comic that proposed cars hook up to the next car ahead using those snap together ball and socket joints like toys have. The first car hooks up to a truck, and everybody rides in a chain. When you get to your destination, you just uncouple. pop! I never understood why that didn’t become popular… ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [March 27, 2024, 5:51pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/24 "2024-03-27T17:51:23Z")
[![](https://media.hswstatic.com/eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL2RhLXZpbmNpLWNhci0yLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6MjkwfSwidG9Gb3JtYXQiOiJhdmlmIn19) ](https://media.hswstatic.com/eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL2RhLXZpbmNpLWNhci0yLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6MjkwfSwidG9Gb3JtYXQiOiJhdmlmIn19) I worked on a project several years ago to build this car per DaVinci’s design. I thought the article would have pasted with the pic. It is a self propelled car. ---
**Author:** ![Left\_Hand\_of\_Dorkness](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/left_hand_of_dorkness/32/7156_2.png) [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)\ **Post date:** [March 28, 2024, 8:52pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/25 "2024-03-28T20:52:43Z")
> [@markn\_1](#): > > When a line of cars is stopped at a light, it’s only necessary for the rearmost car to pull back and wind it up. When it moves forward, it will hit the line of cars in front of it and get them all moving. Physics nitpick: it’ll hit the car in front of it, which will hit the car in front of it, and so on. Only the front car will move. And if it’s going uphill, it’ll go forward a few feet, then roll back down, hitting the line of cars and making the one in back pop off the line and move backward. If THAT’s also uphill, the process will repeat indefinitely, with a series of sharp yet soothing clicking noises. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [March 28, 2024, 8:55pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/26 "2024-03-28T20:55:01Z")
The solution is clearly for the LEAD car to back up, pushing all the others back, winding up all their springs. Then when the light goes green, they all go. It’s like, free energy, man. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [March 28, 2024, 8:57pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/27 "2024-03-28T20:57:33Z")
> [@Left\_Hand\_of\_Dorkness](#): > > the process will repeat **indefinitely** , If only that were so… ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [March 28, 2024, 10:27pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/28 "2024-03-28T22:27:59Z")
It’s all way to complicated. Just have all the roads run downhill. ---
**Author:** ![ZonexandScout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zonexandscout/32/544_2.png) [@ZonexandScout](https://boards.straightdope.com/u/ZonexandScout)\ **Post date:** [March 29, 2024, 1:22pm UTC](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349/29 "2024-03-29T13:22:45Z")
It used to be like that. Just ask my father, who lived at the bottom of the road and had to walk in snow throughout the year. [Previous page](https://boards.straightdope.com/t/pull-back-toy-cars-mechanism-can-replace-electric-city-cars/999349.md?page=1)