[Physics Class Notes] on Force Push and Pull Pdf for Exam

In general terms, we say that the push or pull of an object is force, but what does this mean? 

A force is defined as the application of push or pull on an object with a mass in such a way that it will affect the motion of an object when unopposed. It can cause an object to move from its state of rest, i.e., change its velocity (to accelerate) or can change its direction of movement. It is an interaction that causes or changes the motion of an object. When a force is applied, it has both magnitude and direction. Hence, it is a vector quantity. 

It is denoted by the symbol F and its S.I. unit is Newton (N). The other units of force are dyne,kgwt, etc. 

Now, let us understand the push and pull force in basic language.

What is a Push Force? 

Push is defined as a force that causes an object to move away from the person who is applying the force from its state of rest. When an object is pushed, it tends to move away. Kicking a ball, closing a door, pushing a trolley, and inserting a plug into the socket are all examples of push force.  

Assume that you are asked to push a lawn roller or push the luggage from the stairs and throw it on the floor. For this, you will have to put an effort and that effort you apply through your feet to the object you are pushing is the push force. Applying this force is easier; however, there is another category of force that demands a lot of energy from your end. This force type is called the pull force. Now, let us understand what it is!

What is a Pull Force? 

The pull is defined as a force that causes an object to move towards the person who is pulling the object. Opening a door, plucking the string of a guitar, drawing a bucket of water from the well, and pulling the curtain are all examples of pull force. 

So, this was all about the force in general. Now, let us understand its types.

 

Types of Forces

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A force can be applied to an object in two ways, i.e., by making a contact with the object or by not making a contact with the object. Based on that, there are two types of forces. They are known as contact forces and non-contact forces. 

Contact Force

A contact force is defined as a force that requires a contact to apply a force on an object. Kicking a ball and closing a door are all examples of contact forces because contact is made in each case. It is further classified into three forces, namely, frictional force, applied force, and normal force.

• Frictional Force: When a ball is softly kicked, it rolls over the floor. At that time, a force acts opposite to the direction of the moving ball which eventually stops the ball. This type of force is called frictional force. Generally, it resists the motion of the object when the surface of an object comes in contact with the surface of another object.

• Applied Force: When a person or an object applies force on another object, which results in the movement of the object. It is called an applied force.

• Normal Force: When an object is resting upon a surface, the surface exerts an upward force to balance the force exerted by the weight of the object. The upward force is known as the normal force which is applied by the surface. 

Non-Contact Force 

Non-contact force is defined as a force that is exerted without making any contact. It is further classified into three forces. They are gravitational force and magnetic force. 

• Gravitational Force: The attraction between any two objects with mass is known as gravitational force. It is a natural phenomenon. Stars, planets, and galaxies have an attractive force acting between them all the time. On Earth, physical objects possess weight due to gravity and the ocean tides occur due to the Moon’s gravity.

• Magnetic Force: A magnetic force is defined as a force exerted between two poles of a magnet and also between electrically charged moving particles. It can be either attractive or repulsive.  

Did You Know?

It is assumed often that if an object is at rest, no force is acting on it. But, this is not true. When an object is at rest, there are two forces that  act simultaneously on it. One is the gravitational force which acts downwards and the other one is the normal force which acts upwards. These two forces balance each other. Hence, the net force acting on the ball is zero. Now, if the ball is kicked, then only it will move from its stationary position because an external force greater than the other two forces is applied to it now. Hence, it will move in a particular direction. 

So, this was all about pushing and pulling along with the types of forces. Now, let us assume that your mother asked you to pull heavy luggage from one cart and put them into another cart in the first case. In another situation, she just asks you to drag the luggage, which one would you prefer the easier task? Well, dragging is easier. Here, dragging is a push force, on the other hand, taking out luggage from one cart to another is a pulling force. This is the reason we say that pushing is better than pulling.