5 ms·
The easiest way to see it is to consider the time-reversed version. You chuck the ball up the shape so it perfectly stops balanced at the top. It turns out this
by eigenket 3y ago
The easiest way to see it is to consider the time-reversed version. You chuck the ball up the shape so it perfectly stops balanced at the top. It turns out this is possible for the weird dome in question, but not for pretty much any other shape - including a cone. Going back to time running normally it turns out that this means that a ball balanced perfectly on a cone only has one option consistent with Newton's laws, it'll stay balanced there forever, while there are multiple trajectories consistent with Newton's laws for the dome.
- aidenn0 3y agoWhy is it not possible for a cone? Slide it up the (frictionless) cone with kinetic energy equal to mgh and it should stop on the point.