Contact Force: Simple Definition + Examples (With Pictures)

You already know that Forces are due to an interaction.

(i.e. Whenever two objects interact with each other, they exerts a force)

But, have you wondered how objects interact with each other?

The answer is simple. 

Interaction of an objects can occur in two ways:

When objects are in contact with each other and when they are not in contact with each other.

A force that results when objects are in contact with each other is known as a Contact force.

And

A force that results when objects are not in contact with each other is known as a Non contact force.

Here, I’ll explain the exact meaning of contact force with Real Life examples.

Let’s immediately start off with the definition.

Contact Force Definition

As per the name, you can guess the meaning of this force.

A contact force is a force which requires a contact to occur.

That’s it.

In physics, the definition of contact force can be stated as:

“A force that acts when two objects are physically in contact with each other is known as a Contact Force“

Don’t worry, if you have not understood properly.

Let’s consider some examples to understand the above statement. (So you’ll get a clear idea)

Contact Force Examples in Everyday Life

Here’s a list of Everyday Life examples of contact force:

• Kicking a football

• Throwing a basketball

• Pushing a car

• Leaning against the wall

• Hitting a billiard ball

• Pulling a wooden desk

• Plucking a mushroom from garden

• Flipping a page of book

• Picking a ball from floor

• And more…

In all the above examples, 

Two objects are physically in contact with each other, which results in a Contact Force between them.

Let’s understand the above examples in detail. (One by One)

#1 Kicking a football

Here, a football player is applying some force with his leg to kick the football.

When he kicks the football, two objects football and his leg come in contact with each other.

Which results in a Contact Force between them.

#2 Throwing a basketball

Here, a basketball player is throwing a basketball with his hand.

When he throws the basketball, two objects basketball and his hand come in contact with each other.

Which results in a Contact Force between them.

#3 Pushing a car

Here, a small kid is playing with a toy car.

In order to move a car, he is applying some force with his hand.

When he moves the car, two objects car and his hand comes in contact with each other.

Which results in a Contact Force between them.

#4 Leaning against the wall

Here, a boy is leaning against the wall.

When he lean against the wall, his body applies some force to the wall.

And while leaning against the wall, two objects wall and his body comes in contact with each other.

Which results in a Contact Force between them.

#5 Hitting a billiard ball

Here, a man wants to hit a billiard ball with the stick.

In order to hit a billiard ball, he must have to apply some force with the stick.

So when he hits the ball, two objects stick and a billiard ball comes in contact with each other.

Which results in a Contact Force between them.

#6 Pulling a wooden desk

Here, a boy wants to pull the wooden desk.

To pull the wooden desk, he must have to touch the wooden desk with his hand.

And when he pulls the wooden desk, both wooden desk and his hand come in contact with each other.

Which results in a Contact Force between them.

#7 Plucking a mushroom from garden

Here, a boy is plucking a mushroom from the garden.

When he plucks a mushroom from the garden, he applies some force with his hand.

While plucking the mushroom, two objects mushroom and his hand comes in contact with each other.

Which results in a Contact Force between them.

#8 Flipping a page of book

Here, a boy is flipping the page of a book.

When he flips the page of a book, he applies some force with his hand.

So while flipping the page of a book, two objects page and his hand comes in contact with each other.

Which results in a Contact Force between them.

#9 Picking a ball from floor

Here, a small girl is picking a ball from the floor.

When she picks a ball from the floor, she applies some force with her hand.

And while picking the ball, two objects ball and her hand comes in contact with each other.

Which results in a Contact Force between them.

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There are so many other examples of contact force that we are experiencing in our daily life.

Now let’s discuss the different types of contact forces.

Contact Force Types

Here’s a list of all different types of contact forces:

• Muscular force

• Frictional force

• Tension force

• Applied force

• Normal force

• Air resistance force

• Mechanical force

• Spring force

Let’s understand each one of the above mentioned forces with Real Life examples.

Muscular force

Here, a boy is pushing one heavy stone.

While pushing a heavy stone, he is actually applying some force with his hands.

(i.e., He is actually using his muscles to push a heavy stone)

This type of force is known as a Muscular Force.

To learn more about muscular force, 

Check: Muscular Force

Frictional force

Here, a man is applying the brakes to a bike.

While applying the brakes, tyre and road slides against each other and friction is produced between them.

This friction produces a force which stops the motion of a bike.

This type of force is known as the Frictional Force.

(Frictional force always acts in opposite direction to the motion of an object)

To learn more about frictional force,

Check: Frictional Force

Tension force

Here, a boy is drawing some water from a well with the help of rope.

When he draws the water, the rope gets pulled from opposite ends.

So, a tension is generated in the rope.

Due to this tension, a force is transmitted through the rope.

This force is known as a Tension Force.

To learn more about tension force,

Check: Tension Force

Applied force

Here, a rubber band is stretched by the hand.

When a rubber band is stretched, some amount of force is applied on a rubber band by the hand.

This force applied on a rubber band by the hand is known as Applied Force.

To learn more about applied force,

Check: Applied Force

Normal force

When a wooden chest is placed on a floor, one perpendicular force acts on a wooden chest.

As this force acts perpendicular to the surface of a wooden chest, it is known as a Normal Force.

To learn more about normal force,

Check: Normal Force

Air resistance force

Here, a skydiver is falling downwards. 

When a skydiver falls downwards, one upward force (exerted by air) acts on a skydiver.

This force is known as the Air resistance Force.

To learn more about air resistance force,

Check: Air resistance Force

Mechanical force

Here, a man is drilling a hole into the wall using a drill machine.

In order to make a hole, a drill machine generates some amount of force.

This type of force which is generated by a machine is known as a Mechanical Force.

To learn more about mechanical force,

Check: Mechanical Force

Spring force

When a clickable ballpoint pen is pressed with the hand, some force is generated.

(As the spring inside a ballpoint pen gets compressed)

Due to this force, the point of a pen comes out.

As this force is generated by a spring, it is known as a Spring Force.

Summary

From the above examples, one thing is understood.

There must be a physical contact between the two objects, for a contact force to occur.

That’s how you can easily remember the definition of contact force:

“A force that acts when two objects are physically in contact with each other is known as a Contact Force“

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What do you think, is it easy for you to understand this concept of contact force?

(Let me know in the comments below)

Related:

• What is Force?

• Different Types of Forces

• What is Non contact Force?

• Difference between Contact and Non contact Force