Force and Motion: Definition, Relation and Examples

Force and Motion: In our daily lives, we come across a myriad examples of force and motion. When we throw a ball into the air, it starts moving in a particular direction. In simple words, the push that we give to the ball for it to get displaced is called force and the movement it undergoes from one point to another is called motion.

On the other hand, we can also apply force to halt a moving object. We can bring a cycle to a halt by applying brakes. So force can also be used to stop something. Force and motion are thus, interrelated.

Force and Motion: Definition

Force: The push or pull of an object that causes it to move with a certain velocity.

Motion: The change in the position of a body in relation to its surroundings in a particular time interval.

Force and Motion: Units, Symbols

The SI unit of force is Newton (N)

The symbol of force is F

The SI unit of motion is metre/second or m/s

The symbols of motion can be ‘v’ (velocity) or ‘a’ (acceleration)

Force and Motion: Relation

As said earlier, force is nothing but the push or pull on an object, resulting in the object’s displacement. When we pull something, we draw it closer and when we push something, we only send it farther from us. In both the cases, there is a movement of the object in some direction. So force and motion are like two sides of the same coin.

Also Read: Examples of force in daily life

Newton’s Laws of Motion

It was Sir Isaac Newton who first studied the relation between force and motion and put in place his three laws of motion. Nowadays, these laws may seem very ordinary. However, during his days, these laws were nothing less of being phenomenal.

Newton’s First Law of Motion

A body at rest or in uniform motion continues to be in rest or uniform motion until and unless acted upon by an external force.

In other words, It is the law of inertia.

Newton’s Second Law of Motion

The time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it.

We also call it the law of momentum.

It is here that the formula F = m*a comes into picture.

Newton’s Third Law of Motion

Every action has an equal and opposite reaction.

Examples for Newton’s Laws of Motion

Example for first law: A car being driven at a uniform speed can be brought to a halt by applying brakes.

Example for second law: It takes a smaller force to propel a boat because it is not much heavy. It takes a greater force to propel, say a cruise, because of its heaviness.

Example for third law: When a ball hits the ground, the ground applies an equal and opposite force back on the ball, forcing it to bounce.

More on Force and Motion

So by now, it is more than evident that force can accelerate a body, force can decelarate a body and force can also change the direction of a body. Next time, when you open or close the door of your room, remember how force and motion interact.

Also Read: Types of Motion

We hope this article on Force and Motion help you understand the concepts better. We have given you simple examples so that you can relate these laws to them and apply them better and score better marks in your exams. For more such articles, keep visiting Embibe.