Two friends push with great force against a rock. The forces are equally strong but in opposite directions. A heavy box rests on top of the rock. Rock does not move because equal forces are applied on both sides.
What is force ?
A force is an influence that has the power to alter an object's motion. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to define force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
Force is used to describe a body's tendency to alter or change its condition as a result of an external cause. When force is applied, the body may also alter its size, shape, and direction. kicking a ball, opening and closing doors, or mixing dough are some examples.
Thus, rock does not move because equal forces are applied on both sides.
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