Force and Pressure Class 8 - Chapter 11 CBSE Syllabus 2023-24

Introduction to Force

• A push or pull of an object is known as force, which arises from the interaction between two objects.
• Force has both magnitude and direction, and its strength is expressed in magnitude.
• Force brings about a change in the direction or state of motion of a body.

Types of Force

• A push is a force exerted away from the body, e.g., hitting a snooker ball or kicking a football.
• A pull is a force exerted towards the body, e.g., drawing a bucket of water from a well or playing tug of war.
• Magnetic force is the force of attraction or repulsion between two magnetic bodies due to their poles.

Characteristics of Force

• Force is a vector quantity, expressed in magnitude and direction.
• Vectors are used to find the resultant component acting on a body when multiple forces act on it.
• Net force is the resulting force acting on an object when multiple forces are applied.

Application of Force

• A force can change the state of an object at rest or in motion.
• It can change an object's direction and velocity.
• Force can also change the shape of an object.

State of Motion

• The state of motion of an object is defined by its velocity, which is the speed with a direction.
• Inertia is the tendency of an object to resist changes in its velocity.
• An object at rest or in motion will remain in its state of motion unless an unbalanced force is applied.

Contact Forces

• Contact forces require a touch or contact to be applied, e.g., muscular forces and frictional forces.
• Muscular force is the force applied by the effort of our muscles, e.g., lifting a heavy box or pulling a bucket of water.

Non-Contact Forces

• Non-contact forces do not require a touch or contact to be applied, e.g., gravitational force, electrostatic force, and nuclear forces.
• Electrostatic force is the force of attraction or repulsion experienced by a charged body from another charged body.

Pressure

• Pressure is the force exerted per unit area, and its distribution is affected by the shape of the object.
• Pressure in fluids is transmitted undiminished in all directions on the walls of the container.
• Upthrust or buoyant force is the upward force exerted by a fluid on an object.
• Atmospheric pressure is the pressure exerted by gases in the air on the surface of the Earth.

Explore key concepts related to force and pressure as per the CBSE Class 8 syllabus. Understand the characteristics, types, and effects of force on objects. Test your knowledge on forces and pressures in this chapter.