The Relevance of Newton’s Laws of Motion

Bacolod Cit y Nati onal High School

Sir Isaac Newton’s name has been passed around for a long time, especially because of his three laws of motion, but why are they still studied? The main reason is that classical mechanics, one of the main branches of physics, is built on the laws of motion making it crucial. The study of mechanics focuses on how objects move or remain stationary with the influence of forces.

The first law is also known as inertia, stating that an object at rest will stay at rest and that an object traveling at a constant speed will stay at its current speed unless acted upon by an outside force. Take for example a basketball staying still on the floor ever since you put it down, it stays still until someone or something applies external force on it like kicking it or exerting a small amount of force by lightly pushing it. This explains to us the concept of Newton’s first law.

In Newton’s second law of motion, or the law of acceleration, it is stated that if a net force greater than zero is applied to an object, the object will accelerate (acceleration denotes a change in velocity, either in terms of magnitude, direction, or both). Both the mass of the object and the net force acting on it affect the acceleration of an object. An example is when you’re grocery shopping, pushing a heavy cart slows down your acceleration more than pushing a lighter one would. This is due to the inverse proportionality between acceleration and mass; when an object’s mass increases, its acceleration decreases. The second law shows that two objects with different masses will accelerate at different rates when you apply the same force to them. The smaller mass will experience a higher acceleration compared to the bigger mass. The equation of this law can be regarded as F = ma, where F is the resultant force, m is the mass of the object, and a is the acceleration of the object.

Lastly, the third law of motion also known as interaction, says that for every action (force), there is an equal and opposite reaction (force). If object A exerts a force on object B, object B will also exert a force of the same magnitude but opposite in direction on object A. The third law of motion tells us that forces always come in pairs, and one object cannot exert a force on another without receiving the same-forced force in return. The application of this law can be identified in our daily simple routines, such as walking- when you’re walking on the ground, you push the ground in the backward direction, and the ground in return pushes you in the forward direction, making you walk and explaining this concept.

There is a presence of all these laws in our daily lives. Answering the question why they are still studied, these laws explain exactly how things in our lives move and work.