[Physics Class Notes] on Force – Interaction of Forces Pdf for Exam

Force refers to the fundamental interactions in nature caused by push or pull motions applied on an object by another object. Force and interactions cause a change in the state of an object as well as a change in the velocity and path the object is moving towards. However, the change in velocity can occur two ways, by the increase in the momentum at which the object is moving or by a decrease in the momentum. 

A motion in an object can occur due to several forces, each having a different impact. Where a force is exerted on a non-living object like a ball, it implies applied force. 

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Force- Push or Pull Motions

Effects of Force Interaction

Force and its fundamental interactions in nature result in several effects with the change in movement, velocity, and the direction it moves at. However, there are ample factors that determine its gestures, the shape, and the material of the object are one of the factors. For instance, when a ball is kicked there is a shift in its position due to its hard surface, on the other hand, when a force is applied to a dough or clay material with a softer base, there is a change in its shape. 

An elastic band when stretched changes its shape and bounces back to its original state, when it is released. The materials that retain the shape gained due to forces and their interactions are known as plastic materials, while the materials that change their shape and bounce back to retain their original shape are known as elastic materials. The material and its reaction play a vital role, but so do the types of forces, their implementation, and their outcomes.

Weak Interaction Force

The weak interaction also popularly known as weak nuclear force is fundamental interaction in nature amongst subatomic particles that are held accountable for the radioactive erosion in atoms. The quantum flavour dynamics (QFD) and Electroweak theory (EWT) are the two mainly used theories for the comprehension of weak interaction force.

It further comprises two interactions, charged-current interaction and neutral-current interaction. Some of the weak nuclear force examples are the initiation of the nuclear reaction fueling the sun and the decaying of unstable subatomic substances like mesons.

Strong Interaction Force 

The strong interaction force administers quarks in clusters of subatomic particles like neutrons and protons, it originates with a property known as colour, not to be confused with the general term colour. Particles inclusive of the property function with a strong force while other subatomic particles like leptons and electrons exclusive of the colour property, do not feel any strong forces. Similar to plastic, the force between two quarks elevates in terms of speed with the rise in the distance between the two.

Now, it must be clear that how force and its interaction can result in distinct impacts, the strong and the weak interaction forces explain how subatomic particles also witness interactions. 

Solved Example

What Are Some Examples of Force?

With an extended list of forces, forces are classified among contact forced and non-contact forces. In a contact force, there is a direct physical motion towards the object. Frictional Force and muscular force are two examples of contact forces. The frictional force is the interaction of two surfaces in opposite directions, for example, a rolling ball. Muscular force occurs with the utilization of muscles like the pulling of a rope. 

Likewise, non-contact forces indicate the outcome of any movement without any physical activity. Magnetic, Gravitational, and Electrostatic forces are some of the non-contact forces. Magnetic force is the ability of a magnet to generate motion in another magnet without actually touching it. 

Gravitational force is the simple exertion of force by an object due to its mass attracting it towards the surface of the earth. A classic example of gravitational force is an apple falling from a tree. The electrostatic force is the interaction of a charged object with another charged or uncharged object like the force felt when rubbing a dryer on a cloth.

Did You Know?

• Force is measured in Newton, one force interaction refers to one newton.

• Isaac Newton described the force of interaction with his law called Newton’s second law of motion.

• Forces and their interactions when applied to an object with a weightage, every kg boosts the momentum by a meter.