Forces And Their Interactions
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.
FAQs on Force - Interaction of Forces
1. What does it mean for forces to interact in Physics?
In Physics, an interaction means that a force can only occur when at least two objects influence each other. A force is a push or a pull that one object applies to another. For an interaction to happen, the objects can either be in direct physical contact (like kicking a ball) or influence each other from a distance (like a magnet pulling an iron pin).
2. What is the main difference between contact and non-contact forces?
The main difference lies in whether the objects need to touch.
- Contact forces require physical touching to have an effect. Examples include the friction between a tyre and the road, or the muscular force you use to lift a bag.
- Non-contact forces can act on an object from a distance without any physical contact. Examples include gravity pulling things down or a magnet attracting a piece of metal.
3. Can you give some everyday examples of interacting forces?
Certainly! Interaction of forces is happening all around us. For instance:
- Writing on paper: Your hand applies a force, and the pencil tip interacts with the paper through friction.
- A boat floating: The boat pushes down on the water (gravity), and the water pushes up with a buoyant force.
- Stretching a rubber band: Your fingers apply a muscular force to pull the band, and the band's elastic force pulls back.
4. What is a resultant force and why is it important?
When multiple forces act on an object, the resultant force (also called net force) is the single force that represents the combined effect of all the individual forces. It's important because it tells us how the object's motion will change. If the resultant force is zero, the object's motion won't change. If it's not zero, the object will accelerate in the direction of the resultant force.
5. Why does a bicycle slow down and eventually stop when you stop pedalling?
When you stop pedalling, you remove the forward muscular force. However, opposing forces like air resistance and the force of friction between the tyres and the road are still acting on the bicycle. Since these forces now dominate, they work against the bicycle's motion, causing it to slow down and finally stop.
6. If two children push a box with equal force but from opposite directions, what happens to the box?
The box will not move. This is because the forces are balanced. Since both children are pushing with equal strength in opposite directions, the forces cancel each other out. The resultant force on the box is zero, so there is no change in its state of motion.
7. How is it possible for gravity to act on an apple and make it fall without touching it?
Gravity is a non-contact force. It works through an invisible area of influence called a gravitational field that the Earth generates. The apple, being within this field, experiences a pull towards the Earth's centre. This interaction doesn't require any physical contact, allowing the force to act over a distance and pull the apple down.
8. How do we measure the strength of a force?
The strength of a force is measured by its magnitude. The standard unit for measuring force in the International System of Units (SI) is the Newton (N). A larger magnitude means a stronger force. For example, a force of 20 N is stronger than a force of 10 N.
