How does mg = ma follow from F=ma?

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SUMMARY

The equation F=ma, derived from Newton's Second Law, indicates that the net force acting on an object equals its mass multiplied by its acceleration. In scenarios where gravity is the only force acting on an object, this can be expressed as mg=ma, leading to the conclusion that g=a, where g represents gravitational acceleration. This relationship holds true specifically during free fall, where the only force is gravity. However, other forces such as support force, air resistance, and friction can complicate real-world applications of this principle.

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Can somebody explain in simpler terms F=ma and why that can be writtent as mg=ma. Which finally can be written as g=a.
 
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memsces said:
Can somebody explain in simpler terms F=ma and why that can be writtent as mg=ma. Which finally can be written as g=a.
Newton's 2nd law states that the net force on an object must equal ma. In the special case where the only force on an object is gravity, which equals mg, then the net force is just mg. Thus mg = ma, which implies that g = a. (The acceleration of an object in free fall is g downwards.)
 
Doc_al is correct in saying that g = a when the object is in free fall (the only force acting on the object is gravity). However the world is not that simple, there are a lot more forces that can act on objects such as support force, air resistance, friction just to name a few. So therefore F=ma means the sum of all forces = ma, usually seen with the symbol sigma (meaning the sum of forces) before F. I hope that clarified things for you memsces.
 

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