Transmission of a Force by Means of a Long Stick

Most recent answer: 04/13/2017

Assume we have a very long teeter totter (about 1000 miles), which is made of 12-inch steel girders, and exists completely in a vacuum. If one end is moved, does the other end move exactly simultaneously?
- michael kilpatrick (age 70)

No, the far end of the stick doesn't move instantaneously.   The information from the front end can't reach the far end any faster than the velocity of sound in the material.   For steel this is about 6,000 meters per second or 14,000 miles per hour.  So it would take a little more than a minute and a half before the far end would move.


(published on 04/13/2017)