Let us learn Newton’s Laws of Motion practically in this article. With the help of simple examples discussed in this article, you will begin to understand that these laws are not just confined to our Physics textbooks, but they occur all around us in our everyday lives.
Quick Recap of the Three Laws of Motion
The three laws of motion assist us in explaining how objects behave when they are standing still, when moving and when forces act upon them.
Newton’s First Law of Motion
Newton’s first law of motion suggests that objects do not start moving or stop moving all by themselves. It needs an external force to cause such a change. This attribute of massive bodies resisting variations in their state of motion is known as inertia. To summarise, Newton’s first law of motion states that “a body at rest or uniform motion will continue to be at rest or uniform motion until and unless a net external force acts on it.”
Newton’s Second Law of Motion
The second law of motion tells us what happens to bodies when an external force is applied. Newton’s second law of motion states that the force acting on the body is equal to the product of its mass and acceleration. More precisely, the second law states that “the acceleration of an object is directly proportional to the net force and inversely proportional to the mass of the object.”
Newton’s Third Law of Motion
Newton’s third law of motion defines what happens to a body when it exerts a force on another body. The third law of motion states that “For every action, there is an equal and opposite reaction.” When two bodies interact, they apply force on each other that are equal in magnitude and opposite in direction.
Everyday Examples of the Laws of Motion
This section will discuss some simple everyday life examples and decide which law of motion applies to it. These types of questions are often asked in exams where you are given an example and asked to explain it based on one of the laws.
Fastening of Seat Belts
We have all been asked to fasten our seatbelts when driving the car. Did you know that the logic behind this is Newton’s first law of motion? To explain this, let us consider a situation where a driver has to suddenly apply the brakes. When the brakes are applied, the driver and the passengers sitting in the car will be thrown forward. This happens due to the inertia of motion. When the driver applies the brake, the car will come to a standstill, and you will be still in motion due to the inertia of motion.
While you are walking, Newton’s third law of motion is applicable. When you are walking, your feet exert a backward force. The ground, in turn, applies a forward force on us, pushing us to walk. This is a clear demonstration of the action-reaction pair. Here, the action force is the force that we apply on the ground, and the reaction pair is the force that the ground exerts on us. These two forces are equal and opposite.
Catching the Cricket Ball
When you play a game such as cricket, you are often required to catch the ball on the field. Because a fast-moving ball has significant momentum and catching it might hurt the player’s hands. The standard advice we hear is to move our hands backwards while catching a fast-moving ball. The momentum of the ball has to become zero to catch the ball without hurting our hands. So when the player moves his hands backwards, the time taken to reduce the ball’s momentum to zero increases. As a result, the rate of change of momentum is decreased, and a small force is exerted on the player’.