How does pressure vary with depth in a liquid?

In a liquid, pressure rises with increasing depth because the weight of the liquid above grows as you go deeper. The pressure at any specific depth is influenced by the liquid’s density, the acceleration due to gravity, and the depth itself.

What is atmospheric pressure?

Atmospheric pressure is the force applied by the weight of the Earth's atmosphere on each unit area of the Earth's surface. It decreases with altitude because there is less air above to exert pressure.

How is pressure defined in physics?

Pressure is defined as the force exerted per unit area on a surface. (Pressure=Force/Area)

Why does a straw work for drinking liquids?

A straw functions by lowering the pressure inside when you suck on it. The higher atmospheric pressure outside then pushes the liquid up into the straw, enabling you to drink.

What are the different types of forces?

The main types of forces include: Gravitational Force Frictional Force, Magnetic Force Friction Force Tension Force

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CBSE Notes

Class 8

Science

Chapter 8 Force And Pressure

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CBSE Class 8 Syllabus

Class 8 syllabus allows students to create a structured study plan, allocating time to each subject and topic based on its weightage and importance.

CBSE Class 8 Notes

CBSE Class 8 Notes are important for students who want to prepare effectively for the exam. They are....

CBSE Class 8: A Comprehensive Overview

The Central Board of Education (CBSE) administers the class 8 exam, a prerequisite for all NCERT-based schools to be affiliated with CBSE. The students...

NCERT Solutions Class 8

NCERT Solutions is an important study material, and it provokes the student to revise any topic very efficiently...

CBSE Exam 2026

CBSE is a national-level board of education in India, responsible for public and private school education, and is managed by...

Important CBSE Science Topics

Science is, therefore, a systematic enterprise that organizes and builds testable explanations and predictions...

CBSE Notes

Class 8

Science

Chapter 8 Force And Pressure

CBSE Notes Class 8 Science Chapter 8 Force and Pressure

In physics, force and pressure are foundational concepts that elucidate the interactions between objects and their environments. Grasping these ideas is essential for understanding a range of phenomena, from everyday occurrences to complex scientific principles. While force and pressure are interconnected, they represent distinct concepts that shape our comprehension of and interactions with the physical world.

1.0Download CBSE Class 8 Science Chapter 8 Force and Pressure Notes : Free PDF

Download FREE PDF notes for CBSE Class 8 Science Chapter 8 – Force and Pressure below. This free PDF covers key definitions, formulas, and concepts in a simple, easy-to-learn format.

Class 8 Science Chapter 8 Revision Notes:

2.0Force

Force is an action applied to an object that can alter its state of rest or change its motion.
A push or pull acting on some objects is called a Force.SI Unit of Force is Newton and CGS Unit is Dyne.
1N=105Dyne

3.0Effect of Forces

When two objects interact with each other, a force is exerted between them.
Forces are always exerted by one object on another object i.e to apply force at least two objects are required.
Effect of force depends on both magnitude and direction. Force is a vector quantity. A force vector indicates the direction of the force and its length is proportional to the force's magnitude.
Force can bring a change in the state of motion.
A force can either accelerate or decelerate a moving object.
A force can alter the direction of a moving object.
A force can induce rotational movement in an object.
Force can change the shape of an object.

4.0Types of Forces

Contact Forces-A force that is exerted only when two objects are touching is called contact forces. Some examples of Contact forces are:

Muscular Force-The force resulting due to the action of muscles.
Friction-Force which is responsible for changing the state of motion of objects. Frictional force arises from the contact between surfaces.
Tension- It is a force exerted by string, ropes when they are pulled. When an object pulls on a string or cable, it creates tension, which is the force transmitted through the medium. This force acts along the length of the medium and is directed away from the object creating the pull.

Non-Contact Forces-A non -contact force is a force that one object exerts on another when they are not touching. Some examples of non contact forces are:

Magnetic Force-The force exerted by a magnet on a piece of iron or on another magnet. Similar poles repel each other, whereas opposite poles attract.
Electrostatic Force-The force exerted by a charged body on another charged body or uncharged body is known as electrostatic force. The electrostatic force between two charges can be attractive or repulsive.
Gravitational Force-Gravitational force is the attractive force that exists between any two objects with mass. Objects fall towards earth because it pulls them this force is called gravitational force or force of gravity.

5.0Pressure

Pressure is the force per unit area. It measures how force is distributed over a surface.

$pressure = \frac{F orce}{A re a}$

SI Unit of Pressure is Pascal.
Pressure is inversely proportional to the area of contact, so the smaller the area, the larger is the pressure on a surface for the same force.

6.0Pressure Exerted by Liquid and Gases

Pressure in a liquid is the force exerted per unit area on the walls of its container or on submerged objects. This pressure results from the weight of the liquid above the point where the measurement is taken.
In liquids, pressure increases with depth and is applied uniformly in all directions. This pressure is influenced by the liquid's density, gravitational acceleration, and the depth below the surface.
In gases, pressure is influenced by both the volume and temperature. Changes in either the volume or temperature can cause variations in the gas pressure.

7.0Atmospheric Pressure

Atmospheric pressure is the force exerted by the Earth's atmosphere on each unit area of the Earth's surface. This pressure arises from the weight of the air above and changes with altitude, weather conditions, and other factors.

8.0Key Features of CBSE Notes Class 8 Science Chapter 8 Force and Pressure

Explains the concept of force and its effects on objects.
Covers different types of forces – contact and non-contact.
Describes pressure and how it is exerted by solids, liquids, and gases.
Covers formulas related to pressure and their uses.

Frequently Asked Questions

Join ALLEN!

(Session 2026 - 27)

Name

Mobile Number

Class

Choose class

Goal

Choose your goal

Preferred Programs

Preferred Mode

State

Choose State

I agree to

I authorise ALLEN Career Institute Pvt Ltd to send me regular updates via Phone calls, Whatsapp, SMS, Robocalls (Automated Calls), Emails, or on postal address.

CBSE Class 8 Syllabus

Class 8 syllabus allows students to create a structured study plan, allocating time to each subject and topic based on its weightage and importance.

CBSE Class 8 Notes

CBSE Class 8 Notes are important for students who want to prepare effectively for the exam. They are....

CBSE Class 8: A Comprehensive Overview

The Central Board of Education (CBSE) administers the class 8 exam, a prerequisite for all NCERT-based schools to be affiliated with CBSE. The students...

NCERT Solutions Class 8

NCERT Solutions is an important study material, and it provokes the student to revise any topic very efficiently...

CBSE Exam 2026

CBSE is a national-level board of education in India, responsible for public and private school education, and is managed by...

Important CBSE Science Topics

Science is, therefore, a systematic enterprise that organizes and builds testable explanations and predictions...

CBSE Notes Class 8 Science Chapter 8 Force and Pressure

In physics, force and pressure are foundational concepts that elucidate the interactions between objects and their environments. Grasping these ideas is essential for understanding a range of phenomena, from everyday occurrences to complex scientific principles. While force and pressure are interconnected, they represent distinct concepts that shape our comprehension of and interactions with the physical world.

1.0Download CBSE Class 8 Science Chapter 8 Force and Pressure Notes : Free PDF

Download FREE PDF notes for CBSE Class 8 Science Chapter 8 – Force and Pressure below. This free PDF covers key definitions, formulas, and concepts in a simple, easy-to-learn format.

Class 8 Science Chapter 8 Revision Notes:

2.0Force

Force is an action applied to an object that can alter its state of rest or change its motion.
A push or pull acting on some objects is called a Force.SI Unit of Force is Newton and CGS Unit is Dyne.
1N=105Dyne

3.0Effect of Forces

When two objects interact with each other, a force is exerted between them.
Forces are always exerted by one object on another object i.e to apply force at least two objects are required.
Effect of force depends on both magnitude and direction. Force is a vector quantity. A force vector indicates the direction of the force and its length is proportional to the force's magnitude.
Force can bring a change in the state of motion.
A force can either accelerate or decelerate a moving object.
A force can alter the direction of a moving object.
A force can induce rotational movement in an object.
Force can change the shape of an object.

4.0Types of Forces

Contact Forces-A force that is exerted only when two objects are touching is called contact forces. Some examples of Contact forces are:

Muscular Force-The force resulting due to the action of muscles.
Friction-Force which is responsible for changing the state of motion of objects. Frictional force arises from the contact between surfaces.
Tension- It is a force exerted by string, ropes when they are pulled. When an object pulls on a string or cable, it creates tension, which is the force transmitted through the medium. This force acts along the length of the medium and is directed away from the object creating the pull.

Non-Contact Forces-A non -contact force is a force that one object exerts on another when they are not touching. Some examples of non contact forces are:

Magnetic Force-The force exerted by a magnet on a piece of iron or on another magnet. Similar poles repel each other, whereas opposite poles attract.
Electrostatic Force-The force exerted by a charged body on another charged body or uncharged body is known as electrostatic force. The electrostatic force between two charges can be attractive or repulsive.
Gravitational Force-Gravitational force is the attractive force that exists between any two objects with mass. Objects fall towards earth because it pulls them this force is called gravitational force or force of gravity.

5.0Pressure

Pressure is the force per unit area. It measures how force is distributed over a surface.

$pressure = \frac{F orce}{A re a}$

SI Unit of Pressure is Pascal.
Pressure is inversely proportional to the area of contact, so the smaller the area, the larger is the pressure on a surface for the same force.

6.0Pressure Exerted by Liquid and Gases

Pressure in a liquid is the force exerted per unit area on the walls of its container or on submerged objects. This pressure results from the weight of the liquid above the point where the measurement is taken.
In liquids, pressure increases with depth and is applied uniformly in all directions. This pressure is influenced by the liquid's density, gravitational acceleration, and the depth below the surface.
In gases, pressure is influenced by both the volume and temperature. Changes in either the volume or temperature can cause variations in the gas pressure.

7.0Atmospheric Pressure

Atmospheric pressure is the force exerted by the Earth's atmosphere on each unit area of the Earth's surface. This pressure arises from the weight of the air above and changes with altitude, weather conditions, and other factors.