The "Slinky Drop Problem"
What would you say happens to a slinky that you hold by the top end and let the bottom end go, so the slinky stretches?
- Will the bottom fall first?
- Will the top end fall first?
- Both ends fall together?
- The center of the slinky stay arrest and the bottom and top end will approach each other?
Explanation:
The bottom end, minding its own business. While gravity is pulling it down (green arrow) the tension is pulling it up (red arrow). Both forces are equal, so the bottom end is not moving, until the information (that the tension is changed) reaches the bottom.
[Sources:]
The Channel Veritasium did this riddle a couple of years ago. So, if your interested in Videos and explanation by Derek Muller and Rod Cross from the University of Sydney check their videos out.
Knowledge is the payment our time.