The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
You must have experienced that you need to apply force to the pedal whenever you want the cycle to move ahead. Here, in this case, force is required to set the cycle in motion. Laws of motion will help us in understanding why the object moves or remains still. Laws of motion also tells us why don’t we float through over bed or fall through the floor in our homes.
Contact and Non-contact forces are different in their fundamental nature. Let us talk about them in more detail.
A force that comes into action when two or more objects are in contact is called Contact forces. For example, you are pushing a book kept on the table, and here the book moves because of the applied force when it comes in contact with you.
Non-contact forces come into action even when the objects are not in contact with each other. For example, a ball is freely falling on the ground due to the Earth’s gravitational pull.
Newton’s First Law of motion states that,
For example, if a book is kept on the table, it rests in the same position until we apply force. Similarly, the cycle continues to move on a frictionless road unless we use brakes or a type of force to stop it.
Newton’s First Law of motion is divided into the below parts.
When we apply force on an object, its acceleration changes, and so does its velocity. It brings about a change in the momentum of the object.
Newton’s Second Law of Motion describes that the momentum changes rate is proportional to the quantity of force applied to the object. Also, the direction in which the change occurs is the same as the applied force’s direction.
Newton’s Second Law of Motion is mathematically written as,
It implies that momentum can change when the object’s mass changes or when its velocity changes, or both.
Newton’s Third Law of Motion describes that there is an equal and opposite reaction to every action.
For example, when a book is kept on the table, it exerts its weight(action)on the table. At the same time, the table applies an equal and opposite force(reaction). As a result of which, the book remains on the table.
The attractive force present between two particles owing to their mass is called the Gravitational force of attraction.
The Universal Law of Gravitation describes that the gravitational force acting between the two particles is proportional to the product of their mass. It is inversely proportional to the square of the distance between them.
Consider two particles of mass m1 and mass m2 separated by a distance r. Let F be the attractive force acting between them.
According to the Universal Law of Gravitation,
where G is called the Universal constant of Gravitation=6.67 10-11N m2kg-2
The three Laws of Motion will help us understand how an object moves and stops by applying force. This section has also helped us understand the attractive force between any two particles at a finite distance.