RE: Why knocking is so important.
September 2, 2014 at 5:29 pm
(This post was last modified: September 2, 2014 at 5:31 pm by Anomalocaris.)
He, like you, was talking about net acceleration of an object, not the acceleration of gravity. He doesn't seem to have a clear understanding of what gravity does, and so lumps effects of gravitational force together with effects of other forces and treats them as an amorphous whole.
An object experiences a variety of acceleration components. Acceleration of gravity is just one. Acceleration, or deceleration as result a of drag force is another. Sunlight causing radiation pressure imposes a third acceleration component, if the object is magnetic then the forces of magnetism would cause a forth.
The point is the magnitude and direction of acceleration imposed by gravity (acceleration of gravity) is totally independent of each of these factors, just as each of these factors are independent of any of the others. So acceleration of gravity should not be talked about in a lumpy aggregation of different accelerations. It can be and should be talked about independently.
An object experiences a variety of acceleration components. Acceleration of gravity is just one. Acceleration, or deceleration as result a of drag force is another. Sunlight causing radiation pressure imposes a third acceleration component, if the object is magnetic then the forces of magnetism would cause a forth.
The point is the magnitude and direction of acceleration imposed by gravity (acceleration of gravity) is totally independent of each of these factors, just as each of these factors are independent of any of the others. So acceleration of gravity should not be talked about in a lumpy aggregation of different accelerations. It can be and should be talked about independently.
