Newton’s second law of motion, also known as the law of acceleration, states that the magnitude of the force acting on an object is equal to the product of the mass of that particular object and the acceleration with which it moves. This means that the acceleration produced in a body is directly proportional to the force applied to it and inversely proportional to the mass of the object. The laws of motion were discovered in the year 1687 by an English mathematician, physicist, astronomer, theologian, and author Sir Issac Newton. The laws of motion are mentioned in one of the books written by him called Philosophiae Naturalis Principia Mathematica, commonly known as the Principia. In a nutshell, as per the second law of motion, an object with greater mass accelerates more than an object with lesser mass. Also, it states that with an increase in the force, the acceleration increases and vice-versa.
Examples of Newton’s Second Law of Motion
1. Pushing a Car and a Truck
Newton’s second law of motion can be observed by comparing the acceleration produced in a car and a truck after applying an equal magnitude of force to both. It is easy to notice that after pushing a car and a truck with the same intensity, the car accelerates more than the truck. This is because the mass of the car is less than the mass of the truck.
2. Pushing a Shopping Cart
Pushing an empty shopping cart is easier than pushing a loaded shopping cart. This is because of the relation between the mass of the object, the force applied to it, and the acceleration produced. Since mass has an inverse relationship with acceleration, the loaded cart tends to move at a slower pace than the empty cart.
3. Two People Walking Together
Consider two people, having different masses, walking together. Due to the inverse relationship between mass and acceleration, the person having more mass tends to move slower, and the person having less mass tends to move faster. This scenario justifies Newton’s second law of motion in real life by establishing a relationship between mass, acceleration, and force.
4. Hitting a Ball
A ball develops a certain amount of acceleration after being hit. The acceleration with which the ball moves is directly proportional to the force applied to it. This means that the harder you hit the ball, the faster it will move, thereby demonstrating Newton’s second law of motion in daily life.
5. Rocket Launch
For a rocket to leave the earth’s orbit and enter outer space, a force called thrust is required. As per the second law of motion given by Sir Issac Newton, the force is proportional to the acceleration; therefore, to launch a rocket, the magnitude of thrust is increased, which in turn increases the acceleration. The speed achieved by the rocket finally helps it to escape the earth’s gravitational field and enter space.
6. Car Crash
During a car crash, there exists a force between the obstacle and the car, which is known as the impact force. The magnitude of the impact force depends on the mass of the objects involved in the collision and the speed with which the objects move. This means that the greater be the mass of the objects involved in the collision, the more will be the intensity of the impact force. Similarly, the more be the acceleration with which the car moves, the greater will be the magnitude of the impact force.
7. Object thrown from a Height
When an object is thrown from a certain height, the gravitational pull of the earth helps it to develop acceleration. The acceleration increases as the object advanced towards the earth. According to Newton’s second law of motion, the acceleration developed by a body is directly proportional to the force. When the object hits the ground, the impact force comes into action. This is the reason why a brittle object thrown from a tall building suffers more deformity than the situation where the same object is thrown from a comparatively shorter building.
8. Karate Player Breaking Slab of Bricks
A karate player makes use of the second law of motion to perform the task of breaking a slab of bricks. Since, according to law, the force is proportional to the acceleration, the player tends to move his/her hands over the slab of bricks swiftly. This helps him/her to gain acceleration and produce a proportionate amount of force. The force is sufficient enough to break the bricks.
9. Driving a car
In simple terms, Newton’s second law of motion states that if force is applied to any object that has mass, it will result in the production of an equivalent amount of acceleration in the object. For instance, when we turn on the ignition system of the car, the engine of the car produces sufficient force that enables the car to move with proportionate acceleration.
10. Racing Car
While designing a racing car, the ultimate tendency of the engineers sticks to reduce the mass of the vehicle. This is because, according to Newton’s second law of motion, the mass of an object is inversely associated with acceleration. By reducing the mass of the racing car, the acceleration can be increased considerably, thereby increasing the chance to win the race.