Originally posted by: BitByBit
Originally posted by: Cattlegod
Originally posted by: BitByBit
Circular motion is possibly one of the least understood areas of physics.
There is no such thing as 'centrifugal force'. There is, however, centripetal force.
This is the force required to keep an object in circular motion, and is given by the equation:
F = mv^2 / r
Where v^2 / r gives the acceleration toward the centre of the orbit.
What people call centrifugal force is really inertia.
Simply put, when you are rotating in a circle you are under constant acceleration.
As I implied.
When you are standing on a planet with gravity, you are under constant acceleration. For all intensive purposes, its effects are exactly the same as gravity.
Not quite.
What you feel is the compression caused by gravity and the reaction of the ground you stand on.
Acceleration is caused by an unbalanced force. The force applied to my body due to gravity is exactly balanced by the reaction of the ground. If the ground beneath me were to suddenly disappear, then I would start to accelerate.
When an object is in
orbit however, the acceleration toward the centre of that orbit is caused by an unbalanced force. In a planetary orbit for example, that force is caused by gravity, and is given by
mg.