Could a Roller Coaster Roll Back Down the First Hill?

At the top of the first hill, tipped back in your seat, you think the same thing: what if the chain lets go? This is what holds a roller coaster train on that hill, on its rails and off the train in front, and why, when the power dies, the train still stops. 00:00 Could it roll back? 00:51 What that sound really is 02:03 Nothing pulling, nothing holding 02:49 The coal railway and the first thrill ride 03:42 Why you do not fly off 05:08 From a circle to a teardrop 06:28 What it is really for 07:12 One block, one train 08:12 When a launch comes up short 08:43 Springs, air and magnets 10:10 The morning walk 11:10 Check it yourself Hidden Machines opens up everyday things to show how they really work. #rollercoaster #howitworks #engineering