Gravity Part 4
The apple is still hanging on the tree, and the tree has to exert a force on the apple to keep it from falling, thru the unbroken stem. We can say that the force of gravity has given the apple WEIGHT. If it falls and you try to pick it up, it RESISTS, because gravity wants the apple to accelerate downwards at a rate of 32 (feet per second per second).
However, the apple resists ANY motions that makes it deviate from the motion of just accelerating downwards. Remember the general principle: Gravity acts on the apple with a forcing "grip" to maintain this motion: an acceleration downwards of 32 and an acceleration in all horizontal directions, to the left and right, backwards and forwards, of ZERO.
Let me show you how this gravitational generalization of Newton's 2nd Law of Motion predicts the property known as "mass."
Proving the Relativistic Energy-Momentum relation, the hard way and the easier way.
This adds the proof for the relativistic mass effects from motion, proving that gravity causes it.
