Mach Report This Comment
Date: July 15, 2014 04:14AM
"Well, if I'm here and your here, doesn't that make it, OUR time."
Centrifugal Force - The False Force
An evil word has worked its way into our daily vocabulary, and with it, an
incorrect understanding of the way physics works. "Centrifugal Force"
( Latin for "center fleeing"
is often used to describe why mud gets spun off
a spinning tire, or water gets pushed out of the clothes during the spin dry
cycle of your washer. It is also used to describe why we tend to slide to the
outer side of a car going around a curve. It is a common explanation...the only
problem is all of it is absolutely wrong!!! Centrifugal force does not
exist...there is no such thing...it is a ghost we tend to blame odd behavior
Take for example this common situation. You are riding in a car going around a
curve. Sitting on your dashboard is a cassette tape. As you go around the
curve, the tape moves to outside edge of the car. Because you don't want to
blame it on ghosts, you say "centrifugal force pushed the tape across the
dashboard."--wwrroonngg!! When we view this situation from above the car,
we get a better view of what is really happening. The animation below shows
both views at the same time. The top window shows you the bird's eye view of
the car and the tape, while the bottom window shows you the familiar view from
The car tires on the road have a enough static friction to act as centripetal
force which forces the car to go around the curve. The tape on the slippery
dashboard does not have enough friction to act as a centripetal force, so in the
absence of a centripetal force the tape follows straight line motion. The car
literally turns out from underneath the tape, but from the passenger's point of
view it looks as though something (a ghost force?) pushed the tape across the
dashboard. If the car you are riding in has the windows rolled down, then the
tape will leave the car (or does the car leave the tape?
) as it follows
its straight line path. If the windows are rolled up, then the window will
deliver a centripetal force to the tape and keep it in a circular path.
Edited 1 time(s). Last edit at 15/07/2014 04:18AM by Mach.
pro_junior Report This Comment
Date: July 15, 2014 03:14PM