The concept of force is the most fundamental yet misunderstood subject in physics, particularly among students in upper secondary school. Learning materials in print that describe the formation of these notions, which are officially known as cognition or schemata in Piagetian language, are rarely available to a practicing teacher or to students.
In this paper, we discuss the particular and technical meaning of the idea of force in pre-relativistic classical physics, as well as the existence of many alternative learner conceptions recorded in some research studies. We have given studies on school and college students spanning the years 1983 to 1998 in particular.
Alternative conceptions are taken from these investigations for the purpose of discussion in this presentation. 1. Until the body is in motion, force is associated with it. The concept of force is commonly explained in terms of Isaac Newton’s three laws of motion, which are laid out in his Principia Mathematica (1687).
A body that is at rest or moving at a uniform rate in a straight line will remain in that state until a force is applied to it, according to Newton’s first principle. The second law states that when an external force acts on a body, it causes the body to accelerate (change in velocity) in the direction of the force.
The magnitude of the acceleration is proportional to the magnitude of the external force and inversely proportional to the mass of the body. According to Newton’s third law, when one body exerts a force on another, the second body exerts an equal force on the first.
This action-reaction principle explains why a force tends to deform (i.e., change the shape of) a body whether or not it causes the body to move. When studying the motion of a body, it is common to overlook its deformation.
The presentation is intended to encourage learners to consider, and sometimes question, how we think about and interpret events, without passing judgment on ourselves. Finally, using the concept of force as an example, two important aspects of the scientific method, logical thinking, and curiosity to experiment, are illustrated. Teachers and self-learners alike can benefit from this in their efforts to develop a correct concept of force.
The force acting on a body at rest is zero. Force always moves in the same direction as the body’s velocity. If the velocity changes, the force changes as well. Both centripetal and centrifugal forces act on a body moving in a circle in a uniform manner.
The forces of action and reaction act on the same body. The product of mass and acceleration is defined as a force. Only animated objects, such as people and animals, exert forces; passive objects, such as tables and floors, do not.
A force applied by, say, a hand continues to act on an object even after the object has left. Because force is the fundamental concept of Dynamics, we must first define it before proceeding with Newton’s Laws. A force is (very practically) defined as a push or a pull.
Of course, we are constantly subjected to forces in our daily lives. We exert force whenever we lift something, push something, or otherwise manipulate other objects. A force is a vector quantity because it has a magnitude as well as a direction.
Let us demonstrate the vector quality of a force in practice: when exerting a force, such as pushing a crate, we can change the magnitude of our force by pushing harder or softer.
We can also change the direction of our force by pushing it one way or the other. Because a force is a vector, all of the vector addition and subtraction rules discussed in Vectors apply.
The vector quality of force allows us to manipulate forces in Kinematics in the same way that we manipulated velocity and acceleration. With a formal definition of force in hand, we can now investigate its relationship to motion using Newton’s laws.
Intuitive concept of force
Force is an intuitive concept. Newton’s first law of motion, inertia; momentum and Newton’s second law of motion; impulse; Newton’s third law of motion. Uniform circular motion dynamics: Examples of circular motion and centripetal force (vehicle on a level circular road, vehicle on banked road).
A force is a push or pull applied to an object as a result of its interaction with another object. When two objects interact, a force is exerted on each of the objects. When the interaction is terminated, the two objects no longer feel the force.
Inertia is the body’s inability to change on its own, whether at rest or in uniform motion or direction. An intuitive concept of force, that is, a push or a pull, with magnitude and direction that can vary significantly.
Concept of force and inertia
An object experiences a push or pull as a result of its interaction with another object. When two objects interact, a force is exerted on each of the objects. When the interaction is terminated, the two objects no longer feel the force. The magnitude of the acceleration is proportional to the magnitude of the external force and inversely proportional to the mass of the body.
According to Newton’s third law, when one body exerts a force on another, the second body exerts an equal force on the first. This action-reaction principle explains why a force tends to deform (i.e., change the shape of) a body whether or not it causes the body to move.
When studying the motion of a body, it is common to overlook its deformation.
Inertia is the property of an object that prevents it from changing its state of rest along a straight line unless acted upon by an external force. The inertia of the body increases as its mass increases, and vice versa. Because of inertia, we feel a jerk when we suddenly apply the brakes to a moving car. Thus, Newton’s first law of motion states that an object will remain at rest or in motion unless an external force acts on it. The relationship between acceleration, force, and mass is defined by Newton’s Second Law of Motion.
Newton’s Third Law of Motion states that whenever a force acts from one thing to another, an equal force acts back on the original object. Every action has an equal and opposite reaction, according to this law. When you pull on a rope, the rope pulls back on you as well.
Inertia is a property of a body that opposes any force that attempts to move it or, if it is moving, to change the magnitude or direction of its velocity. Inertia is a feature of a body that allows it to do nothing but oppose active agents like forces and torques.
Concept of force and motion
There are various types of motion associated with the human body. In general physics, the terms force and motion are inextricably linked and represent two sides of the same coin.
For example, the interdependence of force and motion can be seen through the lens of throwing and catching a ball. A force causes interaction between two or more bodies, which results in a change in the state of motion when the interaction is unobstructed.
To understand the relationship that exists between force and motion, we must first understand the terms individually. Every object in the cosmos, according to the universal law of gravitation, exerts a force on others. The following parameter determines the force acting on an object:
The newton (N) or kg·m/s² is the SI unit of force.
Force is symbolized by the letter F.
Vector quantity is a type of quantity.
Assume there are two bodies with masses M and m. They are arranged so that the body with mass m is resting on the body with mass M.
We will say in physics that these two bodies will exert forces on each other. As a result, whenever there is an interaction between two or more bodies, the force will be present.
In nature, force and motion are inextricably linked. To put it another way, force is the cause of motion. If something is moving, we can say that some force is acting on it or that some force must have acted on it to cause it to move.
It is defined as “any interaction that, when unopposed, changes the motion of an object.” It is clear from the definition that force influences an object’s state of motion.
Furthermore, motion is defined as a change in position with respect to time. We can naturally define motion as a change in speed or direction.
Sir Isaac Newton was the first to discover the connection between the two. He concluded that force has the ability to accelerate, decelerate, and change the direction of a moving body.
We can express the relationship between force and motion mathematically using Newton’s second law of motion:
We explain motion using laws of motion, which describe the behavior of particles in motion and are given as:
Overall, force and motion are two inextricably linked concepts. Force can cause acceleration, deceleration, a change in direction, or the complete cessation of motion.
Also read: Important Topic Of Physics: Uniform Velocity
Q. Which is nature’s weakest force?
Ans: Gravity is the weakest force because its coupling constant is so small.
Q. Which force is the most powerful?
Ans: The strong nuclear force, which is 100 times stronger than the electromagnetic force, is the most powerful force.
Q. What are the different types of motion?
Ans: Different objects move in different ways; some in a straight line, others in a curved path, and still others in a different way. Motion is classified into three types based on its nature: linear motion, rotary motion, and oscillatory motion. The object in linear motion moves from one point to another in a straight line or a curved path.