Leaves and Things

I already talked about raking so I decided to do a short thing about what causes the leaves to fall onto the ground in the first place, which is a mix of chemistry and physics. I am not so sure about the chemical part but the leaves turn colors for some reason and they die, and fall of the trees for reasons I don't know, but the physics is somewhat more manageable. If we set up a free body diagram for the leaf on the tree, there would be mass times gravity pulling down, while tension is going up in the stem. Before the leaf falls, the sum of the forces in the leaf is 0 because it is not accelerating, but as the leaf dies the stem grows weaker and the other forces remain the same until it is at the point in where the mass times gravity of the leaf is stronger than the tension in the stem can hold and it breaks. Then the leaf falls to the ground and then once on the ground the normal force of the ground is equal to the force of MG and the leaf rests there until someone rakes it up.