Understanding Force: The Push and Pull Dynamics

Every time you slide a glass of water across a table, slam on a car’s brakes, or kick a football, something fundamental is at work – force. It is one of the most central ideas in physics, yet it is also one of the most misunderstood. Students often think of force as something dramatic – rockets blasting off, cranes lifting steel. But force is happening all around us, constantly and quietly. Understanding it properly is the first step to making sense of how the physical world works.

What is force? 🔗

At its core, force is any action that changes or maintains the motion of an object. The simplest and most useful working definition, especially in a classroom, is this: a force is a push or a pull. When you push a door open or pull a drawer out, you are applying a force. When a magnet draws a pin toward it without any physical contact, that too is a force – just acting at a distance.

In physics, force is formally defined as an action that can cause an object to change its velocity or shape. It has two essential properties: magnitude (how strong it is) and direction (which way it acts). Because it requires both to be fully described, force is called a vector quantity. Saying “a force of 10 Newtons” is incomplete – “a force of 10 Newtons to the right” is a proper description. The SI unit for force is the Newton (N), named after Sir Isaac Newton.

Push and pull: the two faces of force 🔗

Every force is, in essence, either a push or a pull. These two types are opposite in direction but identical in nature – both are interactions that cause objects to change their state.

Push force 🔗

A push force moves an object away from the source applying it. When you kick a football, close a door, or wheel a trolley down a supermarket aisle, you are exerting a push force. The object moves in the direction of the applied push. Machines also use push forces routinely – a hydraulic press uses it to mould metal into specific shapes.

Pull force 🔗

A pull, on the other hand, brings an object closer to the source of the force. Opening a drawer, hoisting a bucket from a well, or pulling back a bowstring – all of these are pull forces. The object moves toward the person or thing applying the force. In a tug-of-war, both teams are applying pull forces on the same rope in opposite directions, which is a vivid demonstration of how forces with direction can work against each other.

How force changes the state of motion 🔗

The most important role of force is that it changes – or initiates – the motion of objects. Forces act on objects as a result of interactions: they can make stationary objects move and cause moving objects to speed up, slow down, or come to a stop. Here are the key effects, each grounded in everyday experience:

Starting motion 🔗

An object at rest will stay at rest unless a force is applied to it. Push a water bottle resting on a desk – it starts moving immediately. The bottle was in a state of rest; the push force broke that state and set it in motion. This is one of the most visible effects of force in daily life. Applying a force to a stationary object can make it move – as seen when you kick a ball lying on the ground or push a shopping cart to start it rolling.

Stopping motion 🔗

Force does not only start motion – it also stops it. When a driver presses the brakes of a car, a braking force (friction between the brake pads and wheels) acts against the car’s motion and brings it to a halt. Applying brakes slows down a moving car because the braking force causes deceleration. Without this opposing force, the car would simply keep moving.

Changing speed 🔗

Force can also increase or decrease the speed of an already moving object. Press the accelerator in a car and the engine applies a forward force, causing the car to speed up. Apply the brakes and the opposing force slows it down. Forces that do not sum to zero can cause changes in an object’s speed or direction of motion. The key here is the idea of net force – the combined effect of all forces acting on an object at a given moment.

Changing direction 🔗

A moving object does not have to stop or speed up – force can simply redirect it. A cricket bat hitting a fast-moving ball is a perfect example. The ball was coming toward the batsman at speed; the force of the bat changes its direction completely, sending it toward the boundary. When you throw a ball, the force of your throw along with the force of gravity determines the ball’s path, continuously redirecting it until it lands.

Force and change in shape 🔗

Force does not only affect motion – it can also alter the physical form of an object. Forces can change an object’s speed, direction, and even its shape – pushing a door open, pulling it closed, or stretching a rubber band all require force. When you squeeze a lump of clay, the force you apply deforms it. Kneading dough is an extended exercise in applying push forces to change shape repeatedly.

When force is applied to an object, it causes a change in shape called deformation. In elastic deformation, the change is temporary – the object regains its shape once the force is removed. A spring that is stretched and released, or a rubber ball that squashes on impact but returns to its round shape, are classic examples of elastic deformation. In contrast, permanently pressing a shape into clay or bending a metal rod causes plastic deformation – the change remains even after the force is removed.

Contact and non-contact forces 🔗

Forces can act in two ways: through direct physical contact, or at a distance without touching. Contact forces require physical interaction between objects, while non-contact forces act at a distance without any physical connection.

Contact forces include muscular force (used when lifting, pushing, or pulling), friction (which opposes the sliding of surfaces against each other), and the normal or reaction force (the push a surface exerts on an object resting on it). Non-contact forces include gravity (which pulls all objects with mass toward each other), magnetic force (which attracts or repels magnetic materials without touching), and electrostatic force (the attraction or repulsion between charged objects). Gravity is the most universally experienced non-contact force – it is what makes a dropped pen fall to the floor every single time.

Balanced and unbalanced forces 🔗

Objects rarely experience just one force. Most of the time, multiple forces act on an object simultaneously. The outcome depends on whether these forces balance each other out or not.

When two or more forces acting on an object cancel each other out – meaning they are equal in magnitude but opposite in direction – they are called balanced forces. When the forces applied to an object are balanced, the net force equals zero and the motion of the object will not change – if the object is at rest, it stays at rest; if it is moving, it continues at the same speed and direction. A book sitting on a table is balanced between gravity pulling it down and the table pushing it up – no net force, no change in motion.

Unbalanced forces produce a net force in one direction, and that is when motion changes. Resultant forces between objects can result in changes to the speed, shape, or direction of one or both of the objects. If two people push a stalled car from behind with a combined force greater than the friction opposing the wheels, the car moves forward – because the forces are now unbalanced in the forward direction.

Force in everyday science teaching 🔗

For teachers, force is one of the most teachable concepts in science because it is so tangible. A force is acting on an object when it changes its shape, speed or direction – and this principle gives teachers a reliable test they can apply to any classroom activity or demonstration. The invisible nature of force is actually an asset in teaching: since we cannot see force directly but can always see its effects, it trains students to reason from evidence – a fundamental scientific skill.

According to NCERT’s approach to science pedagogy at the upper primary stage, scientific concepts should be derived mainly from observations, activities, experiments, and surveys. Force is an ideal topic for this approach. Simple classroom activities – pushing objects of different masses, testing surfaces with different friction levels, stretching rubber bands – provide students with direct, observable evidence of how force works. These experiences build intuition before formal equations are introduced.

The concept of force also naturally leads into Newton’s three laws of motion, which provide a precise mathematical framework for predicting how objects behave under forces. But even before students encounter those laws, a solid grasp of push, pull, direction, magnitude, and the effects of force gives them the conceptual vocabulary to understand motion scientifically rather than just intuitively.

A quick summary of force’s effects 🔗

To bring it all together: a force is any push or pull acting on an object. It is a vector quantity with both magnitude and direction, measured in Newtons. Depending on how it is applied, a force can set an object in motion, bring a moving object to rest, increase or decrease its speed, change its direction of travel, or alter its shape. Forces can act through direct contact or at a distance. When forces on an object are balanced, there is no change in its state. When they are unbalanced, motion changes. These principles underpin everything from how a car brakes safely to how a football curves through the air.

What do you think? When a fielder in cricket catches a fast-moving ball and their hand moves backward as they catch it, which effect of force is at work – and how does the backward motion of the hand relate to the concept of net force? Also, can you identify at least three different effects of force in a single action like kicking a football?

References

1. https://kids.britannica.com/students/article/force/323538
2. https://en.wikipedia.org/wiki/Force
3. https://www.geeksforgeeks.org/physics/push-and-pull-force/
4. https://byjus.com/physics/force-push-and-pull/
5. https://scienceconnections.edu.au/behind-science/physical-sciences
6. https://www.vedantu.com/physics/force-motion-and-state-of-motion
7. https://thewonderofscience.com/ps2a-forces-and-motion
8. https://www.tutorchase.com/answers/igcse/physics/how-do-forces-affect-an-object-s-motion
9. https://www.geeksforgeeks.org/physics/effects-of-force-concept-and-examples/
10. https://www.vedantu.com/physics/force-push-and-pull/
11. https://online-learning-college.com/knowledge-hub/gcses/gcse-physics-help/forces-shape/
12. https://www.teachwire.net/news/how-to-teach-forces-with-confidence-in-primary-science/
13. https://itpd.ncert.gov.in/mss/course_content/Module%2011%20-%20Padagogy%20of%20Science.pdf