In order for an object to accelerate, a forcegravityfrictiona swing must be applied.

In order for an object to accelerate, a force must be applied. It follows Newton’s second law of motion where it states that a body at rest remains at rest unless a force is acted upon it. When you move an object, you are exerting a force onto it. By exerting a force on the object, you are actually displacing it from its initial position. You cannot apply force to the object without altering its position. Keep in mind that when you exert work, you are exerting energy too. 

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