Here's why:
* Newton's Second Law of Motion: This law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically:
* F = ma
* Where:
* F is the net force
* m is the mass
* a is the acceleration
* Resultant Force: This is the vector sum of all the individual forces acting on an object. If the resultant force is not zero, it means there's a net force acting on the object.
* Acceleration: Acceleration is the rate of change of velocity. A non-zero resultant force means there is a net force causing a change in the object's velocity, and therefore, acceleration.
Examples:
* Pushing a box: When you push a box across a floor, you apply a force. If the force you apply is greater than the friction force opposing the motion, there's a net force, causing the box to accelerate.
* Throwing a ball: When you throw a ball, your hand applies a force that accelerates the ball. Once the ball leaves your hand, gravity continues to act on it, causing it to slow down and eventually fall back to the ground.
Key Point: If the resultant force is zero, the object will either be at rest or moving at a constant velocity. This is because there is no net force to cause a change in motion.
