[Physics Class Notes] on Difference Between Force and Pressure Pdf for Exam

Force and pressure are the two basic concepts of Physics which are usually wrongly misinterpreted by people. Force and pressure are different entities, and there are vast differences between them, which you can understand only if you have thorough knowledge. Have you ever thought about how football moves? Or how a drawer opens? This happens when the force is applied to an object. In simple words, force is the pull or push which changes the state of motion or the state of rest or the direction of an object.

Have you ever thought why the tools which are used to cut, trim, chop or pierce items have sharp edges? Have you wondered why heavy vehicles have broad tyres? Here comes the concept of pressure, which is the applied force per unit area. This article provides you with some simple and significant differences between force and pressure.

Definition of Force

Force is the push or pull, which arises due to the physical interaction of two objects, and which changes or tends to change the present state of the object. Force is a vector quantity, i.e. it has both magnitude and direction. The magnitude of force determines the amount of force applied to an object.

In simple words, force is the influence which changes or tends to change the state of motion or rest of the body upon which it is applied. The speed and direction describes the state of the motion. When force is applied to an object, it can change its state of motion or its shape.

 

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When more than one force is applied to an object, the resultant force is called a net Force. When two different forces are subjected to an object in the same direction, then the resultant force is the sum of two forces. And when two different forces are applied in the opposite direction, the resultant force is the difference of the applied forces.

Broadly, the Forces are of Various Types, These are:

• Contact Force

• Muscular Force

• Frictional Force

• Non-contact Force

• Magnetic Force

• Electrostatic Force

• Gravitational Force

Definition of Pressure

The amount of force applied per unit area of a surface is called pressure. In simple words, it is the force acting perpendicularly over the surface of the area, which makes it spread about that area. When force is applied to a large surface area, the pressure is low, and when force is applied to a small area, the pressure is high.

 

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The pressure is the forces spread out by continuous pressing or pushing of two objects with each other. It is calculated as follows:

Pressure = Force / Area

Or, Mathematically: P = F/A

Where:

P is the pressure,

F is the magnitude of the external force, and

A is the surface area of the surface in contact.

Unlike force, the pressure is a scalar quantity, and it has only magnitude. The vector of force acting normal to the surface is the vector element of pressure.

Importance of force and pressure 

The impact of one object over another is Force and the physical quantity of force that is spread over a particular area is Pressure. Force can be defined as a push or a pull that makes an object, or a thing change its state of direction or motion. A force is always applied to a ball when we want to hit the ball, and until the ball is stopped by a motion of gravity, or by friction, the ball will be in motion.

A force can stop a moving object or body, it can make it move faster and it can even make the object or the body change its direction. Force has magnitude and direction.

The physical quantity of force that is spread over a particular area is what we say to be Pressure. Let us take the amount of force that is being applied to an object or a body. If this is divided with the area of contact, then we will get the pressure that is applied to the object or on the body.

We can say that:  pressure=force/area,  which implies that if the same force is applied on an area that is smaller, that will produce a greater pressure compared to when applied to a larger area.