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Name: pete
Status: student
Age: 15
Location: N/A
Country: N/A
Date: 1999 


Question:
If a car accelerates because there is an balanced force acting on it how can it move if for every action there is an equal and opposite reaction?


Replies:
Unbalanced forces would be peculiar, indeed! Let us take two objects, say a horse and planet earth. The horse pushes backward against the earth, and the earth pushes the horse forward with exactly the same magnitude force.

F horse = F earth

mA = Ma

In the horse-earth system, the large mass of the earth results in a small acceleration of the earth, where the small mass of the horse results in a large acceleration.

---Nathan A. Unterman



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