In the second law of Newton , Known as the Fundamental Principle of Dynamics, the scientist states that the larger the mass of an object, the more force will be required to accelerate it.
That is, the acceleration of the object is directly proportional to the net force acting on it and inversely proportional to that of the object.
We know that an object can only accelerate if there are forces on this object. Newton's second law tells us exactly how much an object will accelerate for a given net force.
In other words, if the net force were doubled, the acceleration of the object would be twice as great. Similarly, if the mass of the object were doubled, its acceleration would be reduced by half.
Examples of Newton's Second Law in Everyday Life
This law of Newton applies to real life, being one of the laws of physics that impacts most in our daily lives:
1- Kicking a ball
When we kick a ball, we exert force in a specific direction, which is the direction in which it will travel.
In addition, the stronger that ball is kicked, the stronger the force we put on it and the further away it will go.
2- Capture the ball by hand
Professional athletes move their hands back once they catch the ball as it provides the ball more time to lose its speed, and in turn apply less force on its part.
3- Push a car
For example, pushing a supermarket cart with twice as much force produces twice as much acceleration.
4- Pushing cars
On the other hand, pushing two supermarket trolleys with the same force produces half the acceleration, because this varies inversely.
5- Push the same car full or empty
It is easier to push an empty supermarket cart than a full one, since the full cart has more mass than the empty one, so more force is needed to push the cart full.
6- Pushing a car
To calculate the force needed to push the car to the nearest petrol station, assuming that we move a car of one ton around 0.05 meters per second, we can estimate the force exerted on the car, which in this case will be about 100 Newtons.
7- Driving a truck or a car
The mass of a truck is much larger than that of a car, which means it requires more power to accelerate to the same extent.
When, for example, a car is driven 100km on a highway for 65km, much less petrol will certainly be used than if it had to be driven at the same speed for the same distance in a truck.
8- Two people walking together
The same reasoning above can be applied to any moving object. For example, two people walking together, but one of them has a lower weight than the other, although they walk with the same amount of force, who weighs less will go faster because their acceleration is certainly greater.
9- Two people pushing a table
Imagine two people, one with more force than the other, pushing a table, in different directions.
The person with greater strength is pushing towards the east, and the person with less force towards the north.
If we add both forces, we get a result equal to the movement and acceleration of the table. The table, therefore, will move in a northeasterly direction, although with a greater inclination towards the east, given the force exerted by the strongest person.
10- Playing golf
In a golf game, the acceleration of the ball is directly proportional to the force applied to the club and inversely proportional to its mass. In the way influences the force of the air that can cause a small change in its direction.
Laws of Newton
Isaac Newton (January 4, 1643 - March 31, 1727), English physicist and mathematician, famous for his law of gravitation, was a key figure in the scientific revolution of the seventeenth century and Developed the principles of modern physics .
Newton presented for the first time his three laws of motion in the Principia Mathematica Philosophiae Naturalis In 1686.
Considered the most influential book on physics and possibly on all science, it contains information on almost all essential concepts of physics.
This work offers an accurate quantitative description of moving bodies in three basic laws:
1- A stationary body will remain motionless unless an external force is applied to it;
2- The force is equal to the mass multiplied by the acceleration, and a change of movement is proportional to the applied force;
3- For each action, there is an equal and opposite reaction.
These three laws helped explain not only the elliptical planetary orbits, but almost all other movements in the universe: how planets are kept in orbit by the attraction of the sun's gravity, how the Moon revolves around the Earth and the moons of Jupiter revolve around it and how the comets rotate in elliptical orbits around the sun.
The way most things move can be solved by using the laws of motion: how much force it will take to accelerate a train, whether a cannon ball will reach its target, how air and ocean currents move or whether an airplane will fly , Are all applications of Newton's second law.
In conclusion, it is very simple to observe this second law of Newton in practice, if not in mathematics, since we have all empirically verified that it is necessary to exert more force (and therefore more energy) to move a heavy grand piano than to Slide a small stool across the floor.
Or, as mentioned earlier, when catching a fast moving cricket ball, we know it will do less damage if you move your arm backwards while catching the ball.
You may be interested 10 Examples of Newton's First Law in Real Life .
References
- Jha, A."What is Newton's second law of motion?"(May 11, 2014) in: The Guardian: Isaac Newton. A short history of equations. Retrieved on: May 9, 2017 from The Guardian. Theguardian.com.
- Kane & Sternheim. "Physical". Ed. Revert. 1989.
- Aguilar Peris & Senent"Issues of physics"Ed. Reverte, 1980.
- "Newton's Second Law"Recovered: May 9, 2017 from The Physics Classroom at: physicsclassroom.com.
- "Isaac Newton. Biography"at: Biography.com Retrieved on 9 May 2017 from Biography / biography.com.
- "What is Newton's second law?"In: Khan Academy Retrieved from Khan Academy at: khanacademy.org.
- "Laws of Newton"at SAEM Thales. Andalusian Society of Mathematical Education Thales. Recovered in: May 9, 2017 from thales.cica.es.